| Question: | Which of the following routing protocols do support VLSM?
A. IS-IS
B. OSPF
C. RIPv2
D. EGP
E. BGP
F. IGRP
G. EIGRP
H. RIPv1
|
| Answer: | A. IS-IS
B. OSPF
C. RIPv2
E. BGP
G. EIGRP
|
| Explanation: | RIPv2, EIGRP, OSPF, IS-IS and BGP do support VLSM. |
|
| Question: | Which of the following techniques do distance vector protocols use to avoid routing loops?
A. holddown
B. counting to infinity
C. hop count
D. split horizon
E. flooding
|
| Answer: | A. holddown
D. split horizon
|
| Explanation: | Distance vectors use the following techniques to avoid routing loops:
- Split horizon
- Poison reverse
- Holddown
- Triggered updates
- Aging of routes from the routing table
Counting to infinity is a condition that occurs when a route disappears from the network and is found in distance vector protocols but strictly speaking this is not a technique. |
|
| Question: | EIGRP uses what algorithm to determine path selection?
A. Bellman Ford
B. Dijkstra
C. Diffie-Hellman
D. Diffusing update algorithm
|
| Answer: | D. Diffusing update algorithm
|
| Explanation: | EIGRP uses DUAL or Diffusing Update Algorithm to make path selections. |
|
| Question: | How do we configure over NMBA in broadcast configuration?
A. interface serial1 ip address 10.1.1.1 255.255.255.0 ip router isis encapsulation frame-relay frame-relay map isis 123 broadcast frame-relay map ip 10.1.1.2 123 broadcast
B. interface serial1 ip address 10.1.1.1 255.255.255.0 ip router isis encapsulation frame-relay frame-relay map clns 123 broadcast frame-relay map ip 10.1.1.2 123 broadcast
C. interface serial1 ip address 10.1.1.1 255.255.255.0 encapsulation frame-relay frame-relay map clns 123 broadcast frame-relay map ip 10.1.1.2 123
D. interface serial1 ip address 10.1.1.1 255.255.255.0 ip router isis encapsulation frame-relay frame-relay map clns 123 frame-relay map ip 10.1.1.2 123
|
| Answer: | B. interface serial1 ip address 10.1.1.1 255.255.255.0 ip router isis encapsulation frame-relay frame-relay map clns 123 broadcast frame-relay map ip 10.1.1.2 123 broadcast
|
| Explanation: | We are using the frame-relay map interface configuration command. The keyword IP is used to map the IP destination address to the DLCI and we define the interface as broadcast. Without the CLNS keyword no router appear in the IP routing table because IS-IS does not receive IS-IS frames to populate the IP routing table. |
|
| Question: | Which attributes are not required but if they are in an update all routers running BGP will recognize and act on the information contained?
A. Atomic Aggregate
B. Community
C. Origin
D. AS_Path
E. Next hop
F. Local Preference
G. Aggregator
|
| Answer: | A. Atomic Aggregate
F. Local Preference
|
| Explanation: | A well-known discretionary attribute is not required but when its present in an update all routers running BGP will recognize and act on the information contained. There are the following well-known discretionary attributes:
- local preference
- atomic aggregate |
|
| Question: | How do we redistribute a supernet in BGP without using the aggregate-address command?
A. By creating a static route for the supernet to Null0 and redistribute this route into BGP.
B. This can not be done because BGP does not support VLSM.
C. By redistributing the supernet into a dynamic routing protocol.
D. By creating a static route for the supernet to the BGP speaking router at the egress point of the AS and redistriute this route into BGP.
|
| Answer: | A. By creating a static route for the supernet to Null0 and redistribute this route into BGP.
|
| Explanation: | Using a static route for the supernet pointing to Null0 and then redistributing this into BGP will let BGP advertise this route to its peers. If how ever this route dissappears from the IGP routing table it will still be advertised from BGP and traffic for will enter into the AS but without a destination and travel around the AS untill the TTL is expired and the packet is dropped. |
|
| Question: | How do we configure a default route with administrative distance of 15?
A. ip route 0.0.0.0 0.0.0.0 192.168.1.2
B. ip default-network
C. ip route 0.0.0.0 0.0.0.0 serial0/0 15
D. ip route 0.0.0.0 0.0.0.0 192.168.1.2 distance 15
|
| Answer: | C. ip route 0.0.0.0 0.0.0.0 serial0/0 15
|
| Explanation: | One of the keywords on the ip route configuration command is adding a administrative distance to create a floating static route. |
|
| Question: | OSPF sends out the topology table every ___________ ?
A. 30 minutes
B. 60 minutes
C. 60 seconds
D. 90 minutes
E. 90 seconds
F. 30 seconds
|
| Answer: | A. 30 minutes
|
| Explanation: | OSPF exchanges the full topology table at least every 30 minutes between adjacent routers. |
|
| Question: | Which of the following describes best the synchronization rule in BGP?
A. A router cannot forward a route to an iBGP peer unless the route is in the local IP routing table.
B. A router is synchronized when the iBGP table is the same as the eBGP table.
C. A router can forward a route to an eBGP peer unless the route is in the local IP routing table.
D. A router cannot forward a route to an eBGP peer unless the route is in the local IP routing table.
E. A router can forward a route to an iBGP peer unless the route is in the local IP routing table.
|
| Answer: | D. A router cannot forward a route to an eBGP peer unless the route is in the local IP routing table.
|
| Explanation: | The synchronization rule states that a router cannot forward a route to an eBGP peer unless the route is in its local IP routing table. This requires the IGP and BGP to be synchronized and prevents BGP from advertising routes that the AS cannot direct to the destination. |
|
| Question: | Which of the following rules about policy based routing are true?
A. Policy based routing affects the destination of the packet.
B. Policy based routing examines the source address and should be configured on the inbound interface.
C. Policy based routing can influence how a packet will be routed in a neighboring AS.
D. Policy based routing examines the source address and should be configured on the outbound interface.
E. Policy based routing affects only the next hop in the path to the destination.
F. Policy based routing examines the destination address only and should be configured on the inbound interface.
|
| Answer: | B. Policy based routing examines the source address and should be configured on the inbound interface.
E. Policy based routing affects only the next hop in the path to the destination.
|
| Explanation: | Some rules of policy based routing:
- traffic can be directed on source address or both source & destination address
- affects only the next hop in the path to the destination
- does not affect the destination of the packet, only that path to get there
- does not allow traffic sent into another AS to take a different path from the one that would have been chosen by that AS
- it is possible to influence traffic how to get to a neighboring AS not how it will be routed within that AS
- examines the source address so its configured on the inbound interface |
|
| Question: | Given the following NSAP Address: 49.0005.80.0000a7.0000.ffdd.0004.1921.6801.1005.00 What is the system ID?
A. 0004.1921.6801.1005.00
B. 0004.1921.6801
C. 0005.80.0000a7.0000
D. 1921.6801.1005
E. 0004
F. 49
|
| Answer: | D. 1921.6801.1005
|
| Explanation: | The address is a GOSIP NSAP format:
49.0005.80.0000a7.0000.ffdd.0004.1921.6801.1005.00
__.____.__.______.____.____.____.______________.__
AFI.ICD.DFI.AAI.Reserved.RDI.Area.SystemID.SEL
AFI: Authority and Format Identifier
ICD: International Code Designator
DFI: Domain specific part (DSP) Format Identifier
AAI: Administrative Authority Identifier
RDI: Routing Domain Identifier (Autonomous System Number)
SEL: Network Service Access Point (NSAP) Selector
|
|
| Question: | Wich IS-IS show command will display the metric?
A. show isis database
B. show clns databse detail
C. show isis interface
D. show clns neighbor detail
E. show isis neighbor detail
F. show clns interface
|
| Answer: | F. show clns interface
|
| Explanation: | The show clns interface command will display the Level 1 and Level 2 metric of the outbound interface.
R1# show clns interface ethernet 0
Ethernet0 is up, line protocol is up
Checksums enabled, MTU 1497, Encapsulation SAP
Routing Protocol: ISIS
Circuit Type: level-1-2
Interface number 0x0, local circuit ID 0x1
Level-1 Metric: 10, Priority: 64, Circuit ID: R2.01
Number of active level-1 adjacencies: 1
Level-2 Metric: 10, Priority: 64, Circuit ID: R2.01
Number of active level-2 adjacencies: 1
Next ISIS LAN Level-1 Hello in 5 seconds
Next ISIS LAN Level-2 Hello in 1 seconds
|
|
| Question: | What is the function of a Level 2 IS-IS router?
A. To route traffic between Level 1/2 routers.
B. To locate the destination within an area.
C. To route traffic between areas.
D. To maintain the database.
|
| Answer: | C. To route traffic between areas.
|
| Explanation: | The function of a Level 2 router is to route traffic between areas. |
|
| Question: | Which EIGRP table is build using Hellos?
A. Topology table
B. Routing table
C. Link-state database.
D. Neighbor table
|
| Answer: | D. Neighbor table
|
| Explanation: | The neighbor table is build from information on Hellos received from adjacent routers (neighbors). |
|
| Question: | This state is reached when a router has sent out network packets and is waiting for ACKs from all its neighbors.
A. Dead
B. Stuck in Active
C. Active
D. Passive
|
| Answer: | C. Active
|
| Explanation: | When a router has send out network packets because of a topology change and no Feasible Successor was found it will wait for ACKs from its neighbors. The route is set to active mode. |
|
| Question: | In the EIGRP composite metric the K1 value represents?
A. Loading
B. MTU
C. Delay
D. Bandwidth
E. Reliability
|
| Answer: | D. Bandwidth
|
| Explanation: | The EIGRP Metrics are as follows:
| Symbol | Value | | K1 | Bandwidth | | K2 | Loading | | K3 | Delay | | K4 | Reliability | | K5 | MTU | |
|
| Question: | Which of the following do we find in the neighbor table in EIGRP?
A. Feasible Successors
B. Query
C. Reply
D. Hello time
E. Uptime
F. Smooth return-trip time
G. Holdtime
|
| Answer: | E. Uptime
F. Smooth return-trip time
G. Holdtime
|
| Explanation: | In the neighbor table we find:
- address of the neighbor
- interface where the Hellos was received
- holdtime
- uptime
- sequence number
- SRTT (smooth round-trip time)
- RTO (retransmission timeout)
|
|
| Question: | In order for EIGRP to make adjacencies which conditions have to be met?
A. The sending router must have a different AS number then the receiving one.
B. The metric settings need to be the same
C.
D. The data-link layer protocols must match.
E. The router must hear a Hello packet or ACK from the neighbor.
F. The SRTT must be lower then 10 milliseconds.
|
| Answer: | B. The metric settings need to be the same
E. The router must hear a Hello packet or ACK from the neighbor.
|
| Explanation: | In order for adjacencies to be formed the following conditions need to be met:
- The router must hear a Hello packet or an ACK from a neighbor
- The AS number in the packet header must be the same as that of the receiving router
- The metric settings need to be same. |
|
| Question: | When a route in the EIGRP topology goes down a __________ is sent when there is no FS.
A. ACK
B. Hello
C. Query
D. Update
|
| Answer: | C. Query
|
| Explanation: | Queries are sent out when a route in the topology table goes down and there is no feasible successor. |
|
| Question: | What could cause an EIGRP topology table to be recalculated?
A. The routing table has removed the routes from the topology table to be put in the routing table
B. The topology table received a reply or a query from a neighbor
C. The neighbor table received a reply or a query from a neighbor
D. The neighbor table does not receive a Hello within the holdtime
E. The topology table does not receive a Hello within the holdtime
|
| Answer: | B. The topology table received a reply or a query from a neighbor
D. The neighbor table does not receive a Hello within the holdtime
|
| Explanation: | The following reasons could cause a topology table to be recalculated: - New network is available
- topology table receives an update containing the new network
- interface for a directly connected EIGRP network comes online
- Successor is changed in the topology table and in the routing table
- topology table receives a reply or a query from a neighbor
- the cost of the link changes
- A change from a neighbor when a network has become unavailable
- topology table receives a query, reply or update the remote network is down
- neighbor table does not receive a Hello within the holdtime
- the network is directly connected and the router senses a loss of carrier |
|
| Question: | A router will be marked dead in EIGRP after _____ attempts of sending a unicast query.
A. 16
B. 15
C. 5
D. 30
E. 7
|
| Answer: | A. 16
|
| Explanation: | When a router does not hear an acknowledgment within the alloted time it will retransmit the qeury as a unicast. If after 16 attempts there is no reponse the neighbor will be marked as dead. |
|
| Question: | When can a neighbor become a feasible successor?
A. The topology table hold all routes so all neighbors are feasible successors.
B. If the feasible distance is lower then the advertised distance.
C. If the advertised distance is lower then the feasible distance.
D. If the RTO is lower then the RTP.
|
| Answer: | C. If the advertised distance is lower then the feasible distance.
|
| Explanation: | A neighbor can become a feasible successor only when its advertised distance is less than the feasible distance. This is DUALs key to remain loopfree. |
|
| Question: | This timer is used in EIGRP to determine how long the router waits for an ACK before retransmitting.
A. RTP
B. SRTT
C. RTO
D. Hello
|
| Answer: | C. RTO
|
| Explanation: | The RTO or ReTransmission Timeout is used to determine how long the router waits for an ACK before retransmitting the packet. This timer is calculated in reference to the SRTT (smooth Round-Trip Time). |
|
| Question: | EIGRP uses by default ______ % of the bandwidth.
A. 50
B. 25
C. 75
D. 100
E. 10
|
| Answer: | A. 50
|
| Explanation: | By default EIGRP uses 50% of the bandwidth of the link for its traffic, this value can be configured. |
|
| Question: | We want to see how many EIGRP Updates have been sent and received. Which command do we use?
A. show ip eigrp interfaces
B. show ip eigrp neigbors
C. show ip eigrp neigbors detail
D. show ip eigrp traffic
|
| Answer: | D. show ip eigrp traffic
|
| Explanation: | R1# show ip eigrp traffic
IP-EIGRP Traffic Statistics for process 10
Hellos sent/received: 175/165
Updates sent/received: 9/25
Queries sent/received: 4/0
Replies sent/received: 0/4
Acks sent/received: 15/10
|
|
| Question: | Which of the following messages will not use multicast in EIGRP?
A. Hello
B. Update
C. ACK
D. Query
|
| Answer: | C. ACK
|
| Explanation: | ACK are always sent unicast, it is a Hello packet with no data but the acknowledgment field has a positive number.
Updates can be multicast if there is a change in the topology and unicast if its a reply to a single router.
Hellos and Queries are always multicast. |
|
| Question: | In OSPF interarea summarization is communicated via which LSA(s)?
A. Type 7
B. Type 1
C. Type 2
D. Type 5
E. Type 4
F. Type 3
|
| Answer: | E. Type 4
F. Type 3
|
| Explanation: | LSA type 3 include the networks or subnets within an area that might have been summarized and that are sent to the backbone and between ABRs. Type 4 is information set to the ASBR from the ABR. |
|
| Question: | How do we change the time that Hellos are being sent?
A. R1(config)#router eigrp 10 R1(config-router)#hello-interval 25
B. R1(config)#interface ethernet 0 R1(config-if)#ip hello-timer eigrp 10 25
C. R1(config)#interface ethernet 0 R1(config-if)#ip hello-interval eigrp 10 25
D. R1(config)#interface ethernet 0 R1(config-if)#ip hello-interval eigrp 25
|
| Answer: | C. R1(config)#interface ethernet 0 R1(config-if)#ip hello-interval eigrp 10 25
|
| Explanation: | The ip hello-interval eigrp AS_number seconds interface configuration command will change the how often Hellos are sent to neighbors out of that interface. |
|
| Question: | Changing the bandwidth on an EIGRP enabled interface will have which of the following results?
A. Changes the state of interface
B. Changes the K3 value and therefore the metric calculation.
C. Changes the priority of EIGRP traffic sent over the link
D. Changes the K1 value and therefore the metric calculation.
E. Changes the amount of EIGRP traffic sent over the link
|
| Answer: | D. Changes the K1 value and therefore the metric calculation.
E. Changes the amount of EIGRP traffic sent over the link
|
| Explanation: | By changing the bandwidth statement on an EIGRP interface we change the K1 value and that will result in a new metric calculation. Beause by default EIGRP uses 50% of the available bandwidth for its own traffic that change will result in a change here as well. |
|
| Question: | What does r stand for in the output of show ip eigrp topology?
A. A query packet was sent to this destination
B. An update packet was sent to this destination
C. A reply packet was sent to this destination
D. A query has been sent and the router is waiting for a reply
|
| Answer: | D. A query has been sent and the router is waiting for a reply
|
| Explanation: | Lower case r in the show ip eigrp topology table means that the flag has been set by the software after a query packet was sent and the router is now waiting for a reply.
Router# show ip eigrp topology
IP-EIGRP Topology Table for process 10
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
r - Reply status
P 192.168.1.0 255.255.255.0, 2 successors, FD is 0
via 172.16.80.28 (46251776/46226176), Ethernet0
via 172.16.81.28 (46251776/46226176), Ethernet1
via 172.16.80.31 (46277376/46251776), Serial0
|
|
| Question: | Which of the following are components of EIGRP?
A. Authentication
B. Protocol-independent modules
C. Peer groups
D. Attributes
E. Protocol-dependent modules
F. Neighbor recovery
|
| Answer: | E. Protocol-dependent modules
F. Neighbor recovery
|
| Explanation: | Cisco identifies 4 main components of EIGRP:
- Protocol-dependent modules
- RTP
- Neighbor discovery
- Neighbor recovery
|
|
| Question: | Which of the following statements are true when configuring EIGRP over a NBMA network?
A. EIGRP aggregated traffic over all VCs can be more then the access line speed of the interface.
B. Bandwidth allocated to EIGRP must be the same in both directions on each VC.
C. Bandwidth allocated to EIGRP can be different in both directions on each VC.
D. EIGRP traffic should not exceed the CIR of the VC.
E. EIGRP traffic should not exceed the EIR of the VC.
|
| Answer: | B. Bandwidth allocated to EIGRP must be the same in both directions on each VC.
D. EIGRP traffic should not exceed the CIR of the VC.
|
| Explanation: | When configuring EIGRP over a NBMA cloud Cisco recommends you follow the following rules:
- EIGRP traffic should not exceed the CIR capacity of the VC
- EIGRP aggregated traffic over all VCs should not exceed the access line speed of the interface
- Bandwidth allocated to EIGRP on each VC must be the same in both directions |
|
| Question: | How do we verify if a remote router is configured as a stub with EIGRP?
A. show ip eigrp topology
B. show ip eigrp neighbor detail
C. show ip eigrp stub
D. show ip eigrp interface
E. show ip eigrp database
|
| Answer: | B. show ip eigrp neighbor detail
|
| Explanation: | Router# show ip eigrp neighbors detail
IP-EIGRP neighbors for process 10
H Address Interface Hold Uptime SRTT RTO Q Seq Tye
(sec) (ms) Cnt Num
0 10.1.1.5 Et0/0 12 00:04:48 1832 5000 0 14
Version 12.2/1.2, Retrans:0, Retries:0
Restart time 00:01:05
Stub Peer Advertising ( CONNECTED SUMMARY ) Routes
|
|
| Question: | Which of the following keywords are not used with the EIGRP stub command?
A. no-summary
B. receive-only
C. total
D. connected
E. send-only
F. static
|
| Answer: | A. no-summary
C. total
E. send-only
|
| Explanation: | The EIGRP stub command has the following keywords:
- receive-only, the neighbor is a receive-only router
- connected, the neighbor advertises connected routes
- static, the neighbor advertises static routes
- summary, the neighbor advertises summary routes
|
|
| Question: | We want to change the time a router waits without hearing a Hello from the its neighbor before declaring it unavailable. How do we achieve this?
A. R1(config)#interface ethernet 0 R1(config-if)#ip eigrp hold-interval 10 100
B. R1(config)#interface ethernet 0 R1(config-if)#ip hold-timer eigrp 10 100
C. R1(config)#interface ethernet 0 R1(config-if)#ip eigrp hold-time 10 100
D. R1(config)#interface ethernet 0 R1(config-if)#ip hold-interval eigrp 10 100
E. R1(config)#interface ethernet 0 R1(config-if)#ip hold-time eigrp 10 100
|
| Answer: | E. R1(config)#interface ethernet 0 R1(config-if)#ip hold-time eigrp 10 100
|
| Explanation: | We use the ip hold-time eigrp AS_nr seconds interface configuration command to change the time a router waits without hearing a Hello from a neighbor before declaring that neighbor unavailable. |
|
| Question: | When can we turn off synchronization in BGP?
A. When the network is partial meshed.
B. When the network is not running an IGP.
C. When the local preference attribute is set.
D. When the network is fully meshed.
|
| Answer: | D. When the network is fully meshed.
|
| Explanation: | Synchronization can be turned off if the BGP network is fully meshed. |
|
| Question: | Which attribute is created by a route reflector?
A. Community
B. Multiple Exit Discriminator
C. Originator-ID
D. Origin
|
| Answer: | C. Originator-ID
|
| Explanation: | The optional nontransitive attribute Originator-ID is created by the route reflector. The attribute contains the RID of the router that originated the update and is used to prevent routing loops. |
|
| Question: | When would you not use BGP?
A. Your AS will be a transit domain.
B. There are limited resources on the router.
C. When you are using multiple ISPs.
D. There is a difference in routing policy between you and the ISP.
E. The routing policy between you and the ISP is the same.
|
| Answer: | B. There are limited resources on the router.
E. The routing policy between you and the ISP is the same.
|
| Explanation: | The following are some statements when not to use BGP:
- the organization and ISP use the same routing policy
- multiple redundant links to the ISP but only 1 link will be activated to connect to the Internet
- the routers have limited resources (CPU, memory)
- low bandwidth between the organization and ISP causing the additional routing overhead to interfere with the data |
|
| Question: | Which BGP message is used to inform a peer an error occured?
A. Notification
B. Open
C. Keepalive
D. Update
|
| Answer: | A. Notification
|
| Explanation: | BGP uses the notification message to inform the receiving router of errors that cause the connection to be closed. |
|
| Question: | Which of the following AS numbers are part of the private pool described by RFC 2270?
A. 65510
B. 65495
C. 65560
D. 32123
E. 56412
F. 6600
G. 19200
|
| Answer: | A. 65510
B. 65495
|
| Explanation: | The private AS pool ranges from 64512 - 65535. |
|
| Question: | Which of the following attributes are optional transitive?
A. Community
B. Cluster ID
C. Weight
D. AS_Path
E. Atomic aggregate
F. Aggregator
G. Originator ID
|
| Answer: | A. Community
F. Aggregator
|
| Explanation: | BGP has the following optional transitive attributes:
- Aggregator
- Community |
|
| Question: | Which command would produce the following output?
System Id SNPA Interface State Holdtime Type Protocol
0000.0000.0007 aa00.0400.6408 Ethernet0 Init 277 IS ES-IS
0000.0C00.0C35 0000.0c00.0c36 Ethernet1 Up 91 L1 IS-IS
0800.2B16.24EA aa00.0400.2d05 Ethernet0 Up 29 L1L2 IS-IS
0800.2B14.060E aa00.0400.9205 Ethernet0 Up 1698 ES ES-IS
0000.0C00.3E51 DLCI 123 Serial1 Up 28 L2 IS-IS
0000.0C00.62E6 0000.0c00.62e7 Ethernet1 Up 22 L1 IS-IS
0A00.0400.2D05 aa00.0400.2d05 Ethernet0 Init 24 IS ES-IS
A. show isis neighbors detail
B. show clns snpa
C. show isis neighbors
D. show clns neighbors detail
E. show clns neighbors
F. show isis snpa
|
| Answer: | E. show clns neighbors
|
| Explanation: | R1# show clns neighbors
System Id SNPA Interface State Holdtime Type Protocol
0000.0000.0007 aa00.0400.6408 Ethernet0 Init 277 IS ES-IS
0000.0C00.0C35 0000.0c00.0c36 Ethernet1 Up 91 L1 IS-IS
0800.2B16.24EA aa00.0400.2d05 Ethernet0 Up 29 L1L2 IS-IS
0800.2B14.060E aa00.0400.9205 Ethernet0 Up 1698 ES ES-IS
0000.0C00.3E51 DLCI 123 Serial1 Up 28 L2 IS-IS
0000.0C00.62E6 0000.0c00.62e7 Ethernet1 Up 22 L1 IS-IS 0A00.0400.2D05 aa00.0400.2d05 Ethernet0 Init 24 IS ES-IS |
|
| Question: | Looking at the following output:
R1# show isis database
IS-IS Level-1 Link State Database
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
0000.0C00.0C35.00-00 0x0000000C 0x5696 792 0/0/0
0000.0C00.40AF.00-00* 0x00000009 0x8452 1077 1/0/0
0000.0C00.62E6.00-00 0x0000000A 0x38E7 383 0/0/0
0000.0C00.62E6.03-00 0x00000006 0x82BC 384 0/0/0
0800.2B16.24EA.00-00 0x00001D9F 0x8864 1188 1/0/0
0800.2B16.24EA.01-00 0x00001E36 0x0935 1198 1/0/0
IS-IS Level-2 Link State Database
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
0000.0C00.0C35.03-00 0x00000005 0x04C8 792 0/0/0
0000.0C00.3E51.00-00 0x00000007 0xAF96 758 0/0/0
0000.0C00.40AF.00-00* 0x0000000A 0x3AA9 1077 0/0/0A. That that entry comes from a Pseudonode
B. That that entry comes from a Level 1 only router
C. That that entry comes from a new router still in the process of forming the adjacency
D. That that entry comes from a Level 1-2 router
|
| Answer: | D. That that entry comes from a Level 1-2 router
|
| Explanation: | ATT represents the attach bit. It indicates that the router is also a Level 2 router and it can reach other areas. Level 1 routers use the presence of this bit to identify the closest Level 1-2 router to send their out-of-area data. |
|
| Question: | How can we simplify configuration of multiple neighbors?
A. R1(config-router)#neighbor free-tests peer-group R1(config-router)#neighbor free-tests update-source loopback 0 R1(config-router)#neighbor 10.1.1.1 remote-as 123 R1(config-router)#neighbor 10.1.1.1 peer-group free-tests R1(config-router)#neighbor 192.168.1.1 remote-as 456 R1(config-router)#neighbor 192.168.1.1 peer-group free-tests
B. R1(config-router)#neighbor 10.1.1.1 free-tests R1(config-router)#neighbor 10.1.1.1 remote-as 123 R1(config-router)#neighbor 192.168.1.1 free-tests R1(config-router)#neighbor 192.168.1.1 remote-as 456
C. R1(config-router)#neighbor free-tests peer-group R1(config-router)#neighbor free-tests update-source loopback 0 R1(config-router)#neighbor 10.1.1.1 remote-as 123 peer-group R1(config-router)#neighbor 192.168.1.1 remote-as 456 peer-group
D. R1(config-router)#neighbor peer-group free-tests R1(config-router)#neighbor 10.1.1.1 free-tests R1(config-router)#neighbor 10.1.1.1 remote-as 123 R1(config-router)#neighbor 192.168.1.1 free-tests R1(config-router)#neighbor 192.168.1.1 remote-as 456
|
| Answer: | A. R1(config-router)#neighbor free-tests peer-group R1(config-router)#neighbor free-tests update-source loopback 0 R1(config-router)#neighbor 10.1.1.1 remote-as 123 R1(config-router)#neighbor 10.1.1.1 peer-group free-tests R1(config-router)#neighbor 192.168.1.1 remote-as 456 R1(config-router)#neighbor 192.168.1.1 peer-group free-tests
|
| Explanation: | We can simplify configuration by grouping neighbors that share the same update policy in a peer group.
To use a peer group we follow these steps:
- Create the peer group, neighbor peer_group_name peer-group
- Assign options to the peer group, neighbor peer_group_name option
- Make neighbors member of the peer group, neighbor IP_address peer-group peer_group_name |
|
| Question: | We want to advertise an aggregate route route for 170.0.0.0 but surpress any specific routes. How do we achieve this?
A. aggregate-address 170.0.0.0 255.0.0.0 only
B. summary-address 170.0.0.0 255.0.0.0
C. aggregate-address 170.0.0.0 255.0.0.0 summary-only
D. aggregate-address 170.0.0.0 255.0.0.0
|
| Answer: | C. aggregate-address 170.0.0.0 255.0.0.0 summary-only
|
| Explanation: | To advertise a summary route we use the aggregate-address IP_Address Mask command. Adding the summary-only keyword will surpress ther advertisment of more specific routes to all neighbors. |
|
| Question: | Which command will show the BGP routing table?
A. show ip route bgp
B. show ip bgp route
C. show bgp neighbors
D. show ip bgp
|
| Answer: | D. show ip bgp
|
| Explanation: | The show ip bgp command will display the BGP routing table. |
|
| Question: | Which command will show the BGP topology?
A. show ip bgp
B. show ip bgp topology
C. show ip bgp paths
D. show ip bgp database
|
| Answer: | C. show ip bgp paths
|
| Explanation: | The show ip bgp paths command will display the BGP topology. |
|
| Question: | Which command can we use to make sure that the source address of the route is the transmitting router in BGP?
A. neighbor IP_Address next-hop-self
B. neighbor IP_Address always
C. neighbor IP_Address mask mask next-hop-self
D. neighbor IP_Address remote-as next-hop-self
|
| Answer: | A. neighbor IP_Address next-hop-self
|
| Explanation: | The neighbor IP_Address next-hop-self router configuration command makes sure that the source address of the transmitting router will remain the same when the route is injected on a multiaccess network. |
|
| Question: | Besides having a fully meshed network what could be other reasons to turn off synchronization in BGP?
A. When all routers in the AS are running BGP.
B. When the AS is not a transist AS.
C. When the AS is a transit AS.
D. When the routers at the egress and ingress point are running BGP.
E. When no routes are redistributed into the AS.
|
| Answer: | A. When all routers in the AS are running BGP.
B. When the AS is not a transist AS.
|
| Explanation: | Synchronization can be turned off in BGP when:
- all routers in the AS run BGP
- the AS is not a transit AS
- all the routers inside the AS are meshed |
|
| Question: | How do we turn off synchronization in BGP?
A. R1(config-router)#no synchronization
B. R1(config-router)#no summarization
C. R1(config-router)#no auto-summary
D. R1(config-router)#neighbor ip_address no synchronization
E. R1(config-if)#no synchronization
|
| Answer: | A. R1(config-router)#no synchronization
|
| Explanation: | To turn off synchronization we use the no synchronization router configuration command. |
|
| Question: | When there are multiple route reflectors which attribute is used to identify the originating router?
A. Cluster-ID
B. MED
C. Origin
D. Originator-ID
E. AS_Path
|
| Answer: | A. Cluster-ID
|
| Explanation: | When there are multiple route reflectors in the cluster to provide redundancy the originating router is identified by the Cluster-ID attribute. This attribute is used to prevent routing loops. |
|
| Question: | When a router is configured to forward routing updates to neighbors or peers in the same BGP AS it is called a _____________ ?
A. confederation
B. BGP peering session
C. route reflector
D. adjacency
|
| Answer: | C. route reflector
|
| Explanation: | A route reflector is a router configured to forward routing updates to neighbors or peers within the same AS. |
|
| Question: | The split horizon rule in BGP states?
A. There is no split horizon rule in BGP since all neighbors are configured manually.
B. Updates learned from iBGP peers are not send to other iBGP peers.
C. Updates learned from eBGP peers are not send to other eBGP peers.
D. Only prefixes are redistributed to other iBGP systems.
|
| Answer: | B. Updates learned from iBGP peers are not send to other iBGP peers.
|
| Explanation: | The split horizon rule states that no updates learned from iBGP peers can be sent to other iBGP peers and therefore avoid routing loops. |
|
| Question: | What are benefits of the BGP synchronization rule?
A. reduces network resources
B. consistency within the AS
C. reduces routing updates
D. reduces unnecessary traffic
E. removes the need for an IGP
|
| Answer: | B. consistency within the AS
D. reduces unnecessary traffic
|
| Explanation: | A few benefits of synchronization are:
- prevents traffic from being forwarded to unreachable destinations
- reduces unnecessary traffic
- ensures consistency within the AS |
|
| Question: | When will an iBGP router propogate a route to a BGP neighbor?
A. When the route is redistributed from an IGP.
B. When the route is received from another iBGP router.
C. When the network command is used.
D. When the route is summarized.
E. When the route has the longest prefix match of all paths to the destination.
|
| Answer: | A. When the route is redistributed from an IGP.
C. When the network command is used.
|
| Explanation: | An iBGP router will propagate a route to another BGP neighbor when: - the advertised route was generated by the transmitting router via one of the following methods: - via the network command - redistributed from an IGP - redistributed static routes - the advertised route is a connected route |
|
| Question: | Which of the following are benefits of using route reflectors?
A. reduction of network traffic
B. no need for an IGP
C. faster convergence
D. no need for synchronization within the AS
|
| Answer: | A. reduction of network traffic
C. faster convergence
|
| Explanation: | Some benefits of route reflectors are: - improved scalability of the network - strong hierarchical design - reduction of network traffic - reduction of memory and CPU resources - faster convergence |
|
| Question: | How do we configure a route reflector?
A. R1(config-router)#neighbor ip_address route-reflector-client
B. R1(config-router)#neighbor ip_address route-reflector
C. R1(config-router)#neighbor ip_address route-reflector-client remote-as AS_number
D. R1(config-router)#neighbor ip_address route-reflector remote-as AS_number
E. R1(config-router)#network ip_address route-reflector-client remote-as AS_number
|
| Answer: | A. R1(config-router)#neighbor ip_address route-reflector-client
|
| Explanation: | To configure a route reflector we use the neighbor ip_address router-reflector-client router configuration command. |
|
| Question: | We want to send a full BGP update to a specific peer. How do we achieve this?
A. R1#clear ip bgp ip_address in
B. R1#clear ip bgp *
C. R1#clear ip route bgp
D. R1#clear ip bgp ip_address out
|
| Answer: | D. R1#clear ip bgp ip_address out
|
| Explanation: | In order to let the BGP routing process send a full update to a peer we use the clear ip bgp neighbor_address out command. |
|
| Question: | How do we configure the router so that BGP peering sessions are not torn down when new configurations are implemented?
A. R1(config-router)#neighbor neighbor_address soft-configuration inbound
B. R1(config-router)#neighbor neighbor_address soft-configuration
C. R1(config-router)#neighbor neighbor_address configuration inbound
D. R1(config-router)#neighbor neighbor_address soft-inbound
|
| Answer: | A. R1(config-router)#neighbor neighbor_address soft-configuration inbound
|
| Explanation: | We can configure BGP to store the prefixes before the policy application.
This requires more memory but allows new configurations to be implemented without tearing down the BGP peering sessions.
In order to achieve this we use the neighbor neighbor_address soft-configuration inbound router configuration command.
Because this is on a per-neighbor basis and only for inbound updates we use the inbound keyword. |
|
| Question: | Why would we use policy-based routing in BGP?
A. To reject or accept selected routes.
B. To set attributes to influence path selection.
C. To make decisions based on Next-Hop and Origin attribute.
D. To make decisions based on router resources.
|
| Answer: | A. To reject or accept selected routes.
B. To set attributes to influence path selection.
|
| Explanation: | Reasons for applying policy-based routing in BGP are:
- to make decision based on AS Path, Community or the prefix
- to reject or accept select routes
- to set attributes to influence the path selection |
|
| Question: | Which of the following statements are true about prefix lists?
A. There is no implicit deny at the bottom of every prefix list.
B. When there are multiple entries in the prefix list that match the prefix the highest sequence number is used.
C. If a route is permitted then the route is used.
D. A sequence number does not need to be specified when removing an entry.
E. Sequence numbers have to be manually configured.
|
| Answer: | C. If a route is permitted then the route is used.
D. A sequence number does not need to be specified when removing an entry.
|
| Explanation: | Prefix permitting or denying is based on the following rules:
- if the route is permitted it is used
- if the route is denied it is not used
- there is an implicit deny any at the bottom of every prefix list
- when multiple entries of a prefix list match a given prefix, the entry with the smallest sequence number is used
- the router begins the search for a match at the top of the prefix list, if a match is made the search stop
- sequence numbers are automatically generated by default
- sequence numbers do not need to be specified when removing a configuraton entry |
|
| Question: | Which prefix list parameter do we use when the prefix is greater than or equal to the value stated in the list?
A. le
B. len
C. ge
D. seq
|
| Answer: | C. ge
|
| Explanation: | The ge parameter is used if the prefix is greater than or equal to the value stated in the list. |
|
| Question: | We want to know if there are any matches against our configured prefix lists. Which command do we use?
A. show ip bgp prefix-list
B. show bgp prefix-list
C. show bgp prefix-list detail
D. show ip bgp prefix-list summary
E. show ip prefix-list detail
|
| Answer: | E. show ip prefix-list detail
|
| Explanation: | R1# show ip prefix-list detail allowed
ip prefix-list allowed:
Description: allowed-list
count: 1, range entries: 0, sequences: 10 - 10, refcount: 3
seq 10 permit 10.0.0.0/8 (hit count: 0, refcount: 1) |
|
| Question: | If we want to allow all prefixes between /8 and /16 how do we configure the prefix-list?
A. ip prefix-list test permit 0.0.0.0/0 ge 8 le 16
B. ip prefix-list test permit 0.0.0.0/0 le 16 ge 8
C. ip prefix-list test permit 0.0.0.0 ge 8 le 16
D. ip prefix-list test permit 0.0.0.0/0 le 16
|
| Answer: | A. ip prefix-list test permit 0.0.0.0/0 ge 8 le 16
|
| Explanation: | In order to allow all prefixes between /8 and /16 we use the ip prefix-list prefix_list_name permit 0.0.0.0/0 ge 8 le 16 router configuration command. The ge value is the lower limit so the allowed/denied prefixes have to be greater in value then the ge value but smaller then the le value. Therefore we can say the le value is the upper limit for the prefixes. |
|
| Question: | Besides the weight attribute we can use another attribute to influence the path out of the AS when we have multiple paths. How do we achieve this?
A. bgp default next-hop ip_address
B. bgp default local-preference value
C. bgp local-preference value
D. bgp default AS_Path value
|
| Answer: | B. bgp default local-preference value
|
| Explanation: | We can use the bgp default local-preference router configuration command to inform the routers iBGP peers of the preferred exit path from the AS when there are multiple paths. The default value is 100. |
|
| Question: | How can we verify that certain BGP attributes (e.g. weight) have changed after configuration?
A. show ip bgp attributes
B. show ip bgp summary
C. show bgp attributes
D. show ip bgp
|
| Answer: | D. show ip bgp
|
| Explanation: | The show ip bgp command shows the BGP attributes and their values. This will verify any configuration changes made to tweak the BGP configuration. |
|
| Question: | How do we configure R1 to allow 10.1.0.0/16 to be processed by BGP?
A. R1(config-router)#neighbor ip_address prefix-list allowed in R1(config)#ip prefix-list allowed permit 10.1.0.0/16
B. R1(config-router)#neighbor ip_address prefix-list allowed in R1(config-if)#ip prefix-list allowed permit 10.1.0.0/16
C. R1(config-router)#neighbor ip_address prefix-list allowed in R1(config-router)#ip prefix-list allowed permit 10.1.0.0 255.255.0.0
D. R1(config-router)#neighbor ip_address prefix-list allowed in R1(config-router)#ip prefix-list permit 10.1.0.0/16
|
| Answer: | A. R1(config-router)#neighbor ip_address prefix-list allowed in R1(config)#ip prefix-list allowed permit 10.1.0.0/16
|
| Explanation: | To configure a router to use a prefix list as a filter in distributing routes we use the neighbor ip_address prefix-list prefix_list_name in | out router configuration command. To configure the prefix list we use the ip prefix-list name deny | permit network/len global configuration command. |
|
| Question: | We want to create a prefix list that denies all prefixes between 192.168.1.0/20 and 192.168.1.0/24. How do we achieve this?
A. ip prefix-list test deny 192.168.1.0/20 ge 24
B. ip prefix-list test deny 192.168.1.0/24 le 20
C. ip prefix-list test deny 192.168.1.0 ge 20 le 24
D. ip prefix-list test deny 192.168.1.0/20 le 24
E. ip prefix-list test deny 192.168.1.0/24 ge 20
|
| Answer: | D. ip prefix-list test deny 192.168.1.0/20 le 24
|
| Explanation: | When there is no ge value specified the prefix list uses only the prefixes between the len value and the le value. If no ge and le value is specified an exact match is assumed. |
|
| Question: | In a multihomed AS and accepting only the default route from the ISPs how does BGP select the best path to the external network?
A. By using the gateway with highest local-preference attribute.
B. By using the AS_Path attribute that selects the exit path to the Internet.
C. By using the Originator-ID attribute that selects the exit path to the Internet.
D. By using the gateway that advertised the route.
|
| Answer: | D. By using the gateway that advertised the route.
|
| Explanation: | In a multihomed AS and accepting only the default route from the ISPs BGP select the best path to the external network by using the gateway that is advertising the route. |
|
| Question: | If there are multiple paths to the same destination how can we influence them using the Ciscos proprietary attribute?
A. R1(config-router)#neighbor ip_address med value
B. R1(config-router)#neighbor ip_address local-preference value
C. R1(config-router)#neighbor ip_address weight value
D. R1(config-router)#neighbor ip_address remote-as as_number weight value
|
| Answer: | C. R1(config-router)#neighbor ip_address weight value
|
| Explanation: | Weight is Ciscos proprietary attribute in BGP. The higher the value of this attribute the better the path. We use the neighbor ip_address weight value router configuration command to change the weight attribute. The default value is 32768 and the range extends from 0 to 65535. |
|
| Question: | Which of the following BGP attributes are used in optimal path selection?
A. Originator ID
B. Community
C. Origin
D. Local Preference
E. Atomic Aggregate
F. Aggregator
G. Next Hop
|
| Answer: | C. Origin
D. Local Preference
G. Next Hop
|
| Explanation: | BGP uses the the following attributes in path selection:
- Origin
- AS_Path
- Next Hop
- Multiple Exit Discriminator
- Local Preference
- Weight |
|
| Question: | Which OSPF debug command can we use to view the DR selection?
A. debug ospf events
B. debug ip ospf summary
C. debug ip ospf events
D. debug ip ospf adjacencies
|
| Answer: | C. debug ip ospf events
|
| Explanation: | The debug ip ospf events command will display information on OSPF related events such as adjacencies, DR selection, flooding information, SPF calculation. |
|
| Question: | If we do not want to use an OSPF debug command but still want receive syslog messages when adjacencies are changed which command do we use?
A. log-adjacency
B. log-adjacency-all
C. log-adjacency-changes ospf
D. log-adjacency-changes
|
| Answer: | D. log-adjacency-changes
|
| Explanation: | The log-adjacency-changes router configuration command will send syslog messages when adjacencies are changed. This command requires less resources then the debug commands. |
|
| Question: | We want to know when the last time SPF was executed on our IS-IS router. Which command do we use?
A. show log
B. show is-is spf-log
C. show is-is spf
D. show clns spf-log
E. show clns spf
|
| Answer: | B. show is-is spf-log
|
| Explanation: | The show is-is spf-log command will display the last 20 occurences that triggered a SPF calculation on the router. |
|
| Question: | How can we display Sequence Number Packets in IS-IS?
A. debug is-is events
B. show is-is packet
C. debug is-is statistics
D. debug is-is update-packets
|
| Answer: | D. debug is-is update-packets
|
| Explanation: | The debug is-is update-packets will display sequence number packets (CSNP and PSNP) and LSPs that are detected by the router. |
|
| Question: | We want to see the Hellos exchanged by our EIGRP router. How do we achieve this?
A. debug eigrp neighbors
B. debug ip eigrp neighbors
C. debug ip eigrp
D. show ip eigrp
E. debug ip eigrp traffic
|
| Answer: | A. debug eigrp neighbors
|
| Explanation: | The debug eigrp neighbors command will display Hello packets sent and received by the router and neighbors discovered via this process. |
|
| Question: | We want to control the BGP traffic by filtering out autonomous systems. How can do this?
A. Use of Autonomous System path access-lists
B. Use of Autonomous System path prefix-lists
C. Use of Autonomous System path distribute-lists
D. Use of Extended access-lists
|
| Answer: | A. Use of Autonomous System path access-lists
|
| Explanation: | We can use AS Path access-list to filter on Autonomous Systems. |
|
| Question: | What can we minimize the effect of flapping BGP routes?
A. Implement route dampening
B. Nothing
C. Implement prefix-lists
D. Increase the time between Keepalive messages
|
| Answer: | A. Implement route dampening
|
| Explanation: | When a route starts flapping this a damaging to the BGP table because of the extra network traffic and CPU resources used by the router. By implementing route dampening a flapping route will be considered an ill-behaved route and will get a penalty every time it flaps. If the penalties exceed a configured limit that route will be dampened. |
|
| Question: | Which command can we use to verify the BGP peer is using the correct table version?
A. show bgp ip_address
B. show ip bgp table ip_address
C. show bgp neighbors ip_address
D. show ip bgp neighbors ip_address
|
| Answer: | D. show ip bgp neighbors ip_address
|
| Explanation: | The show ip bgp neighbors ip_address will display that the neighbors has been updated with that version of the primary BGP routing table. |
|
| Question: | If our BGP network consists of 15 routers and we want to make this a fully meshed network how many sessions would there be?
A. 100
B. 110
C. 105
D. 210
E. 225
|
| Answer: | C. 105
|
| Explanation: | We use the following formula to calculate the amount of sessions in a fully meshed network:
n(n-1)/2 in this case 15(15-1)/2 = 105 sessions. |
|
| Question: | Which command will advertise routes into the BGP process?
A. network network
B. neighbor network mask network_mask
C. network network network_mask
D. network network mask network_mask
|
| Answer: | D. network network mask network_mask
|
| Explanation: | The network network mask network_mask router configuration command will identify which networks to be advertised by BGP. |
|
| Question: | When there is no sharing of information between routing processes we call this ______________ ?
A. Areas
B. Redistribution-less
C. Ships in the night
D. Autonomous systems
|
| Answer: | C. Ships in the night
|
| Explanation: | When there is no sharing of network information between the routing processes it is referred to as ships in the night routing. |
|
| Question: | Why would there be more then 1 routing protocol running in the same organization?
A. Faster convergence
B. Smaller networks with different protocols are more stable
C. Transition between routing protocols
D. Host based solutions that need a different protocol
|
| Answer: | C. Transition between routing protocols
D. Host based solutions that need a different protocol
|
| Explanation: | Following are some reasons why an organization might run more then 1 routing protocol:
- It is transitioning between routing protocols
- It used to be a collection of small networks and are merging to 1 large network
- Host based solutions might require a different protocol, e.g. Unix hosts needing RIP to find gateways
- The organization has acquired another organization and the networks merge
- Different network administrator implemented different routing protocols
|
|
| Question: | The default seed metric of IS-IS is?
A. infinity
B. 20
C. 10
D. 0
|
| Answer: | D. 0
|
| Explanation: | | Routing Protocol | Default Seed Metric | Action | | RIP | infinity (since IOS 12.1) | no routes entered in the routing table | | IGRP | infinity | no routes entered in the routing table | | EIGRP | infintiy | no routes entered in the routing table | | IS-IS | 0 | routes entered in the routing table | | OSPF | 20 (type2) but from BGP 1(type 2) | routes entered in the routing table | | BGP | MED is given the IGP metric | routes entered in the routing table | |
|
| Question: | When a route is redistributed into another routing protocol without metrics defined it is assigned?
A. The metric remains the same
B. The same metric as the receiving protocol
C. The seed metric
D. The metric assigned is the average of metrics used by the receiving routing protocol
|
| Answer: | C. The seed metric
|
| Explanation: | The seed metric is assigned to all routes received into another routing protocol through redistribution. |
|
| Question: | How can we change the administrative distance of a routing protocol?
A. R1(config-router)#distance value default
B. R1(config-router)#administrative-distance value
C. R1(config-if)#distance value
D. R1(config-router)#distance value
|
| Answer: | D. R1(config-router)#distance value
|
| Explanation: | To change the administrative distance of a routing protocol we use the distance value router configuration command. |
|
| Question: | Which of the following statements about redistribution are true?
A. When a route is redistributed it inherits the administrative distance of the new routing protocol.
B. When a route is redistributed it inherits the metrics of the new routing protocol.
C. When more then 1 routing protocol is running on the router the route with the best administrative distance will be placed in the routing table.
D. When a route is redistributed the new routing protocol considers this route as an internal route.
|
| Answer: | A. When a route is redistributed it inherits the administrative distance of the new routing protocol.
C. When more then 1 routing protocol is running on the router the route with the best administrative distance will be placed in the routing table.
|
| Explanation: | The following rules are important to consider when using redistribution:
- When a route is redistributed it inherits the administrative distance of the new routing protocol.
- When more then 1 routing protocol is running on the router the route with the best administrative distance will be placed in the routing table.
- When a route is redistributed the new routing protocol considers this route as an external route.
- In order for a route to be redistributed it must have an entry in the routing protocol from where it originates |
|
| Question: | Which of the following could be problems occuring when using route redistribution?
A. Routing loops
B. Faster convergence
C. Suboptimal routing
D. Optimal routing
E. Simple configuration
|
| Answer: | A. Routing loops
C. Suboptimal routing
|
| Explanation: | Some of the problems that can occur when using route redistribution:
- Suboptimal routing could occur when the wrong or less efficient routing decision is made
- Routing loops could occur
- Convergence time of the network increases because of the different technologies used
- The decision-making process and the information sent within the protocols could incompatible and could lead to errors and complex configuration |
|
| Question: | In RIP, an interface that listens to updates but doesnt send any is a __________ interface.
A. quiet
B. silent
C. passive
D. dampened
|
| Answer: | C. passive
|
| Explanation: | A passive interface is an interface that doesnt participate in the routing process. In RIP and IGRP it will listen to updates but wont send any, in EIGRP and OSPF it will not send or listen to Hellos so no adjacencies will be formed. |
|
| Question: | When redistributing in EIGRP and using the default-metric command, in what order are the composite metrics applied?
A. First,Second,Third,Fourth,Fifth
B. Bandwidth,Delay,Reliability,Loading,MTU
|
| Answer: | B. Bandwidth,Delay,Reliability,Loading,MTU
|
| Explanation: | When redistributing in EIGRP, composite metric is assigned with the default-metric bandwidth delay reliability loading mtu command. |
|
| Question: | How do we change the administrative distance of EIGRP?
A. R1(config)#router eigrp 10 R1(config-router)#distance eigrp 80 150
B. R1(config)#router eigrp 10 R1(config-router)#distance eigrp 80 150 default
C. R1(config)#router eigrp 10 R1(config-router)#eigrp-distance 80
D. R1(config)#router eigrp 10 R1(config-router)#distance 80 150
|
| Answer: | A. R1(config)#router eigrp 10 R1(config-router)#distance eigrp 80 150
|
| Explanation: | In order to change the administrative distance of EIGRP we use the distance eigrp internal-distance external-distance in router configuration mode. |
|
| Question: | When using the redistribute command we can specify the metric-type. For which routing protocol is this necessary?
A. RIP
B. OSPF
C. IS-IS
D. BGP
E. EIGRP
|
| Answer: | B. OSPF
|
| Explanation: | The metric-type keyword of the redistribute command is used by OSPF. It is used to specify the external link type, type 1 or type 2, associated with the default route advertised into OSPF. |
|
| Question: | How do we configure a candidate default path?
A. ip default-network network
B. ip default network
C. ip network network
D. ip default-network network network_mask
|
| Answer: | A. ip default-network network
|
| Explanation: | When a router is not directly connected to the default network but does have a route to it, it is considered a candidate default path. We can configure multiple candidate paths with the ip default-network network global configuration command. |
|
| Question: | Given the network 192.168.1.0/24 what will be subnetmask if we only want 20 hosts on each subnet?
A. /30
B. /29
C. /27
D. /28
|
| Answer: | C. /27
|
| Explanation: | In order for us to get 20 hosts on each subnet we need 5 bits of the last octet this will give us 2^5 - 2 = 30 hosts on each subnet. We still have 3 bits left for available subnets. So the subnetmask is 255.255.255.224 or /27. |
|
| Question: | EIGRP uses which multicast address for updates?
A. 224.0.0.9
B. 224.0.0.6
C. 224.0.0.1
D. 224.0.0.10
E. 224.0.0.5
|
| Answer: | D. 224.0.0.10
|
| Explanation: | EIGRP uses 224.0.0.10 for sending out routing updates. |
|
| Question: | In IS-IS what best describes a pseudonode?
A. The LAN identifier for a broadcast subnetwork.
B. A router that is only connected to the backbone and provide transit traffic between areas.
C. A group of routers running the IS-IS protocol.
D. A service at the network layer to which the packet is to be directed.
|
| Answer: | A. The LAN identifier for a broadcast subnetwork.
|
| Explanation: | A pseudonode is the LAN identifier for a broadcast subnetwork. It makes the broadcast domain appear as a virtual router and the routers appear as connected interfaces. |
|
| Question: | Which of the following statements are true about IS-IS?
A. LSPs are acknowledged on a LAN
B. Seven types of LSPs
C. IS-IS is an IP application.
D. Bounderies are defined on the router.
E. Boundaries are defined on the link.
F. 2 types of LSPs
|
| Answer: | E. Boundaries are defined on the link.
F. 2 types of LSPs
|
| Explanation: | In IS-IS the area and host address are assigned to the whole router so the boundaries are on the link. There are two types of LSP (Link-state packet) Level 1 and Level 2. |
|
| Question: | When a router has multiple routes to a network what will be used to route a packet to that network?
A. The route that matches the longest prefix length.
B. The route that was learned first.
C. The route that matches the shortest prefix length.
D. The route that was learned last.
E. The route that uses the fastest interface.
|
| Answer: | A. The route that matches the longest prefix length.
|
| Explanation: | The forwarding process will use the route where the most number of subnet bits match that of the destination network. This is known as match to the longest prefix length. |
|
| Question: | Which of the following are part of the switching function in a router?
A. Check if the frame passes the crc.
B. Check if there is a layer 2 address.
C. Check if there are multiple equal-cost paths.
D. Check for the best path to the destination.
|
| Answer: | A. Check if the frame passes the crc.
B. Check if there is a layer 2 address.
|
| Explanation: | The switching function on a router performs the following steps:
- checks the incoming frame for validity
- checks if it contains a layer 2 address to the router
- checks the size of the frame, not too big or too small
- checks if it passes the cyclic redundancy check
- strips the layer 2 header and trailer and checks the destination address against its cache
- creates the new frame header and trailer and places the frame in the outbound interface queue |
|
| Question: | Which of the following are routed procotols?
A. IPX
B. SPX
C. NetBeui
D. IP
E. IS-IS
F. TCP
G. OSPF
H. AppleTalk
I. BGP
|
| Answer: | A. IPX
D. IP
H. AppleTalk
|
| Explanation: | A routed protocol is the layer 3 protocol used to transfer data from one end device to another across the network. AppleTalk, IPX, IP, Vines, DECnet IV are examples of routed protocols. |
|
| Question: | Which command allows us to change the forwarding decision made on entries in the routing table?
A. ip classless
B. ip route-cache
C. ip source-route
D. match ip route-source
|
| Answer: | A. ip classless
|
| Explanation: | On by default, since IOS 12.0, the ip classless command changes the forwarding decisions made on entries in the routing table, it does not change how the routing table is built. |
|
| Question: | What is described by the following:
A value assigned to each path based on the criteria specified in the routing protocol.
A. Bandwidth
B. Subnetmask
C. Prefix length
D. Path cost
E. Metric
F. Administrative Distance
|
| Answer: | E. Metric
|
| Explanation: | The metric is a value assigned to each path based on the criteria specified in the routing protocol. |
|
| Question: | Looking at the routing table we see routes marked with i, via which protocol are these routes learned?
A. IGRP
B. EIGRP
C. OSPF
D. BGP
E. IS-IS
|
| Answer: | E. IS-IS
|
| Explanation: | Routes that are marked with an i in the routing table are routes learned via IS-IS.
R1# show ip route
Codes:
I - IGRP derived, R - RIP derived, O - OSPF derived,
C - connected, S - static, E - EGP derived, B - BGP derived,
* - candidate default route, IA - OSPF inter area route,
i - IS-IS derived, ia - IS-IS, U - per-user static route,
o - on-demand routing, M - mobile, P - periodic downloaded static route,
D - EIGRP, EX - EIGRP external, E1 - OSPF external type 1 route,
E2 - OSPF external type 2 route, N1 - OSPF NSSA external type 1 route,
N2 - OSPF NSSA external type 2 route |
|
| Question: | The maximum amount of equal-costs paths on a Cisco router is by default?
A. 6
B. 2
C. 4
D. 8
E. 10
|
| Answer: | C. 4
|
| Explanation: | On a Cisco router, if multiple equal-cost paths exist in IP up to 6 paths can be used to load balance traffic across the network in a round-robin manner. The default is 4 paths. |
|
| Question: | We want to enter a static route in the routing table that will stay there even if the interface shuts down. How do we achieve this?
A. ip route 192.168.1.0 255.255.255.0 172.16.1.1
B. ip route 192.168.1.0 255.255.255.0 serial0/1
C. ip route 192.168.1.0 255.255.255.0 172.16.1.1 persistent
D. ip route 192.168.1.0 255.255.255.0 172.16.1.1 permanent
|
| Answer: | D. ip route 192.168.1.0 255.255.255.0 172.16.1.1 permanent
|
| Explanation: | Using the permanent keyword with the ip route command ensures that the route will not be removed from the routing table even if the interface shuts down. |
|
| Question: | Which of the following are valid statements for implementing static routes?
A. The network administrator needs control over the link.
B. Using static routes makes scalability easier.
C. The network is a stub network.
D. Static routes are more reliable since there is no convergence in case of a failure.
E. Static routes are easier to confgure no matter what the size of the network is.
|
| Answer: | A. The network administrator needs control over the link.
C. The network is a stub network.
|
| Explanation: | Some reasons for implementing static routes are:
- low bandwidth link, e.g. dial-up links
- you need control over the link
- the link is a backup to the dynamically learned route
- there is only 1 path to the remote network, a stub network
- router has limited resources and can not run a routing protocol
|
|
| Question: | ODR uses which protocol to send prefixes from the remote router to the core router?
A. Static routing
B. EIGRP
C. IGRP
D. CDP
E. SNMP
|
| Answer: | D. CDP
|
| Explanation: | ODR or On Demand Routing uses Cisco Discovery Protocol (CDP) to send the prefixes of attached networks from the spoke or remote router to the hub or core router. |
|
| Question: | By default ODR sends updates every 60 seconds we want this to decrease to 30 seconds. How do we achieve this?
A. R1(config-if)#cdp timer 30
B. R1(config)#ODR timer 30
C. R1(config-if)#ODR timer 30
D. R1(config-if)#timer 30
|
| Answer: | A. R1(config-if)#cdp timer 30
|
| Explanation: | Because ODR, On Demand Routing, uses CDP (Cisco Discovery Protocol) we can change the update interval by changing the CDP timer to send out updates more or less frequently then every 60 seconds (default). |
|
| Question: | Networks logically grouped together under one administrative control is called a(n) _________ ?
A. Backbone
B. Area
C. Domain
D. Workgroup
E. Hierarchy
F. Autonomous system
|
| Answer: | F. Autonomous system
|
| Explanation: | An autonomous system is a logical grouping of networks under one administrative control. |
|
| Question: | We want to create 15 subnets of the 172.16.0.0/16 address. How many hosts are available on each subnet?
A. 2046
B. 2048
C. 2050
D. 2044
|
| Answer: | A. 2046
|
| Explanation: | To give us 15 subnets we use 5 bits of the host portion giving us 30 available subnets [2^5 - 2 = 30]. This leaves us 11 bits available for hosts, 2^11 - 2 = 2046 hosts on each subnet. |
|
| Question: | What is the network address, host range and broadcast address of the 4th subnet of the given network 192.168.1.0/27? [do include subnet-zero]
A. Network 192.168.1.96 host range 192.168.1.97 - 192.168.1.126 broadcast 192.168.1.127
B. Network 192.168.1.64 host range 192.168.1.65 - 192.168.1.94 broadcast 192.168.1.95
C. Network 192.168.1.96 host range 192.168.1.97 - 192.168.1.127 broadcast 192.168.1.128
D. Network 192.168.1.128 host range 192.168.1.129 - 192.168.1.158 broadcast 192.168.1.159
|
| Answer: | A. Network 192.168.1.96 host range 192.168.1.97 - 192.168.1.126 broadcast 192.168.1.127
|
| Explanation: | We are using 3 bits of the last octet for subnetting so this leaves us 5 bits for hosts. The first 3 bits are set to 000 for the first subnet. So the first subnet has hosts 1 to 30 in binary 0 0001 to 1 1110
As we know the broadcast is all 1?s, this gives us 0001 1111 or 31 so for the first subnet the broadcast address is 192.168.1.31
Now the 4th subnet, the 3 bits used for the subnet position are set to 011 and again 5 bits for hosts on this subnet.
The network is 0110 0000 or 96 giving us 192.168.1.96
Now the host range, the first host is 0110 0001, or 97, the last host is 0111 1110 or 126
The broadcast, 01 11 1111 or 127 giving us 192.168.1.127 |
|
| Question: | What are some advantages of using prefix routing?
A. eliminates the need for an exterior routing protocol.
B. greater flexibility in network addressing.
C. eliminates the need for route summarization
D. reduction in the size of the routing table.
E. allows for complex routing protocols to be used on private networks.
|
| Answer: | B. greater flexibility in network addressing.
D. reduction in the size of the routing table.
|
| Explanation: | Following are some benefits of Prefix Routing/CIDR:
- reduces the routing table in size
- allows for more flexibility in network addressing
- less overhead in network traffic, CPU and Memory |
|
| Question: | Which of the following routing protocols do not support VLSM?
A. EGP
B. BGP-4
C. IGRP
D. RIPv2
E. OSPF
F. RIPv1
G. IS-IS
|
| Answer: | A. EGP
C. IGRP
F. RIPv1
|
| Explanation: | The following routing protocols support VLSM:
- RIPv2
- OSPF
- IS-IS
- EIGRP
- BGP-4
|
|
| Question: | Ciscos hierarchical design consists of which layers?
A. Access
B. Backbone
C. Distribution
D. Network
E. Core
F. Internetwork
|
| Answer: | A. Access
C. Distribution
E. Core
|
| Explanation: | The Cisco hierarchical design model has the following layers:
- The core layer
- The distribution layer
- The access layer
|
|
| Question: | Which of the following elements would find on the core layer of Ciscos hierarchical design?
A. Access-lists
B. QoS
C. NAT
D. Redundancy
E. Complex routing decisions
|
| Answer: | B. QoS
D. Redundancy
|
| Explanation: | The core layers main function is to connect the entire enterprise by interconnecting the distributions layer devices. To achieve maximum availability we need a highly redundant layer. Any services, e.g. filtering (Access lists), NAT etc. should be removed from this layer since they create a latency in the forwarding process. To ensure higher priority to certain traffic types QoS can be implemented at this layer. |
|
| Question: | Distribution lists can be used to achieve which of the following?
A. To change the priority of a packet when it travels across the network.
B. To change the metrics of routes redistributed in another routing protocol.
C. To tag routes being redistributed from one routing protocol in another.
D. Prevent routing loops when redistributing between multiple routing protocols.
E. Hide networks, e.g. labs, secure networks, to be advertised to the whole network.
|
| Answer: | D. Prevent routing loops when redistributing between multiple routing protocols.
E. Hide networks, e.g. labs, secure networks, to be advertised to the whole network.
|
| Explanation: | Distribute lists are access lists applied to the routing process to determine which networks will be accepted in the routing table or sent in updates. The can also function to control security, overhead and management reasons. |
|
| Question: | Which form of queuing has a threshold stating the number of bytes or packets that might be sent before servicing the next queue?
A. Class-Based weighted fair queuing
B. Low-Latency queuing
C. Cisco express forwarding
D. Weighted fair queuing
E. Custom queuing
F. Priority queuing
|
| Answer: | E. Custom queuing
|
| Explanation: | In custom queuing the interface buffer is divided into 16 queues. Each queue has a threshold stating the number of bytes or packets that might be sent before servicing the next queue. |
|
| Question: | Besides access lists we can use an another method to reduce network traffic that is not so demanding on resources as access lists. Which method is that?
A. null interface
B. offset list
C. distribution list
D. custom queueing
|
| Answer: | A. null interface
|
| Explanation: | A null interface is virtual or logical interface that exists only in the operating system of the router, any traffic send to it disappears because the interface has no physical layer. By disabling ICMP Unreachable messages sent in response to packets send to the null interface the packets are silently dropped, i.e. no error message is sent to the transmitting device. |
|
| Question: | Which are some features of IPv6?
A. Complex header
B. No need for multicast addresses
C. Part of the IPv6 address is the NICs MAC address
D. Autoconfiguration
E. Security
|
| Answer: | D. Autoconfiguration
E. Security
|
| Explanation: | IPv6 has the following, and more, benefits and features:
- larger address space
- autoconfiguration
- renumbering
- security
- mobility
- simple and efficient header
- ... |
|
| Question: | In NAT terminology what is described by the following: "These addresses allow hosts in the organization to communicate"
A. Outside local
B. Outside global
C. Inside local
D. Inside global
|
| Answer: | C. Inside local
|
| Explanation: | Inside local addresses allow for each end device in the organization to communicate. These addresses are unique within the enterprise but they are probably not globally unique. They are the inside addresses as seen locally within the enterprise. |
|
| Question: | What does ::1 represent in IPv6?
A. Unspecified and Loopback
B. Link local
C. Aggregate global unicast
D. Site local
|
| Answer: | A. Unspecified and Loopback
|
| Explanation: | The unspecified and loopback IPv6 unicast address is represented 0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.0000.0001 or
0.0.0.0.0.0.0.0.0.0.0.1 or
::1
It is often uses to download software or requesting an address. The loopback address is used to test the interface in basic troubleshooting. |
|
| Question: | The first 48 bits of an IPv6 address are used for?
A. To create an easy transistion from IPv4
B. To create the multicast range.
C. To enter the MAC Address of the host.
D. To create the aggregate global unicast.
|
| Answer: | D. To create the aggregate global unicast.
|
| Explanation: | The first 48 bits of an IPv6 address is the header used by the IANA for external routing within the Internet to create the aggregate global unicast. If this 48-bit prefix is not used the addressing scheme is similar to IPv4 private addressing. |
|
| Question: | Which of the following routing protocols support IPV6 on a Cisco router?
A. RIPng
B. RIPv2
C. BGP-4
D. EIGRP
E. OSPF
F. RIPv1
G. IS-IS
H. IGRP
|
| Answer: | A. RIPng
C. BGP-4
E. OSPF
G. IS-IS
|
| Explanation: | From Ciscos IOS 12.2T and later release the following routing protocols support IPv6:
- RIPng
- OSPF
- IS-IS
- BGP-4
|
|
| Question: | Which attribute can cause problems on a multiaccess network?
A. Aggregator
B. AS_Path
C. Origin
D. Next hop
E. Community
|
| Answer: | D. Next hop
|
| Explanation: | In eBGP, the next hop is the IP Address, specified in the neighbor command, of a router from outside the AS advertising into the AS. On a multiaccess network, if a route came from one router, it would be unwise for another router to advertise that route with its own IP Address as the source, this could lead to packets flooding the network before finding the true originator. The rule therefore is that the address of the router the originally sent the update onto the multiaccess network should remain the source address. |
|
| Question: | How do we configure RIP so the routes redistributed from OSPF have a metric of 2?
A. R1(config)#router rip R1(config-router)#redistribute ospf 10 metric-type 2
B. R1(config)#router rip R1(config-router)#redistribute ospf 10 R1(config)#router ospf 10 R1(config-router)#default-metric RIP 2
C. R1(config)#router rip R1(config-router)#redistribute ospf 10 default-metric 2
D. R1(config)#router rip R1(config-router)#redistribute ospf 10 R1(config-router)#default-metric 2
|
| Answer: | D. R1(config)#router rip R1(config-router)#redistribute ospf 10 R1(config-router)#default-metric 2
|
| Explanation: | If we do not specify a metric value in the redistribute command we can set a default metric for redistribution into OSPF, RIP or BGP using the default-metric value router configuration command. |
|
| Question: | What can you use to filter routing updates out of the routing process?
A. Passive-interface
B. Static routes
C. Distribute lists
D. Default routes
|
| Answer: | C. Distribute lists
|
| Explanation: | Distribute lists are access-lists applied to the routing process to determine which networks are entered in the routing table or are send in updates. |
|
| Question: | Of the routes being redistributed in our network we do not want the 10.1.0.0/16 network for security reasons. How do we configure the router to achieve this?
A. R1(config)#router ospf 10 R1(config-router)#redistribute eigrp metric-type 2 R1(config-router)#distribute-list 10 in R1(config)#access-list 10 deny 10.1.0.0
B. R1(config)#router ospf 10 R1(config-router)#redistribute eigrp metric-type 2 R1(config-router)#distribute-list 10 in
C. R1(config)#router ospf 10 R1(config-router)#redistribute eigrp metric-type 2 R1(config-router)#distribute-list 10 out R1(config)#access-list 10 deny 10.1.0.0
D. R1(config)#router ospf 10 R1(config-router)#redistribute eigrp metric-type 2 R1(config-router)#distribute-list 10 in R1(config)#access-list 10 permit 10.1.0.0
|
| Answer: | A. R1(config)#router ospf 10 R1(config-router)#redistribute eigrp metric-type 2 R1(config-router)#distribute-list 10 in R1(config)#access-list 10 deny 10.1.0.0
|
| Explanation: | We use a distribute-list to filter out the network. The distribute-list will refer to an access list that permits or denies a network to be entered in the routing table |
|
| Question: | Which of the following are part of the DSP in IS-IS?
A. IDI
B. Area ID
C. NSEL
D. High Order DSP
E. System ID
F. AFI
|
| Answer: | C. NSEL
D. High Order DSP
E. System ID
|
| Explanation: | The DSP or Domain Specific Part consists of:
- High Order DSP
- System ID
- NSEL
|
|
| Question: | Which command do we use to view the parameters of the routing procotols active on the router?
A. show ip protocols
B. show protocols
C. show route protocols
D. show ip route protocols
|
| Answer: | A. show ip protocols
|
| Explanation: | The show ip protocols will display the parameters and current state of the active routing protocol process(es). |
|
| Question: | How do we enable WFQ on an interface with a speed higher then 2Mbps?
A. Weighted-fair-queue
B. Fair-queue enable
C. Weighted-fair-queue enable
D. Fair-queue
|
| Answer: | D. Fair-queue
|
| Explanation: | To enable weighted fair queueing (WFQ) for an interface, use the fair-queue interface configuration command. WFQ is enabled by default on interfaces that have a bandwidth of 2.048Mbps or less. |
|
| Question: | Which utility do we use to identify where a problem is in the network?
A. Show ip route
B. Ping
C. Telnet
D. Trace
|
| Answer: | D. Trace
|
| Explanation: | The trace utility will identify where there is a problem in the network. Where the trace utility fails indicates a good starting point to troubleshoot the problem. |
|
| Question: | When would you use route maps?
A. To control bandwidth
B. To define policies in policy-based routing
C. To define more granular access lists
D. To control redistribution
E. To implement BGP
|
| Answer: | B. To define policies in policy-based routing
D. To control redistribution
|
| Explanation: | Route maps can be used for the following:
- To control redistribution
- To control and modify routing information
- To define policies in policy-based routing
- To add granularity in the configuration of NAT
- To implement BGP policy-based routing |
|
| Question: | Which of the following statements are true about route maps?
A. Only extended access lists can be used with route maps.
B. A route map checks the criteria from highest sequence number to lowest.
C. At the end of a route map there is an implicit permit and not an implicit deny like access lists.
D. When a match is made the route map stops, just like access lists.
E. A route map has a list of criteria defined with the match statement.
|
| Answer: | D. When a match is made the route map stops, just like access lists.
E. A route map has a list of criteria defined with the match statement.
|
| Explanation: | Route maps can use standard and extended IP access list and just like access lists they have an implicit deny at the end.
Again, like access list, route maps are checked sequencially starting at the lowest number. |
|
| Question: | When will a set command be applied in the route map?
A. When there is no match criteria specified but the route map is a deny.
B. When the packet match the criteria and the criteria is set to deny.
C. When the packet doesnt match the criteria but the criteria is set to deny.
D. When the packet match the criteria and the criteria is set to permit.
|
| Answer: | D. When the packet match the criteria and the criteria is set to permit.
|
| Explanation: | The set command will only be applied if the statement is marked as permit and the packet meets the criteria. |
|
| Question: | What are some disadvantages of policy-based routing?
A. Additional CPU and memory resources needed.
B. Load balancing can not be implemented
C. Extra configuration is needed.
D. QoS can not be implemented
E. More powerfull routers mean a bigger financial cost.
|
| Answer: | A. Additional CPU and memory resources needed.
C. Extra configuration is needed.
|
| Explanation: | Some disadvantages of policy-based routing are:
- A backup path should be in place in case the defined next-hop router goes down
- Additional CPU is required to examine every source address to effect the defined policy
- Extra configuration is required
- Possibility exists that other traffic will be affected |
|
| Question: | How do we "enable" a route map for incoming traffic?
A. R1(config-if)#ip route-map route_map_name
B. R1(config-if)#ip policy route-map route_map_name
C. R1(config)#ip policy route-map route_map_name
D. R1(config-router)#ip policy route-map route_map_name
|
| Answer: | B. R1(config-if)#ip policy route-map route_map_name
|
| Explanation: | When a route map has been configured we use the ip policy route-map route_map_name interface configuration command for to enable it for incoming traffic. |
|
| Question: | Which set statement is not supported in fast-switched policy-based routing?
A. Set ip tos
B. Set ip precedence
C. Set default interface
D. Set ip next hop
E. Set ip default next hop
|
| Answer: | E. Set ip default next hop
|
| Explanation: | When using fast-switched policy-based routing the set ip default command is not supported. |
|
| Question: | How do we enable fast-switched policy-based routing?
A. R1(config-router)#route-cache policy
B. R1(config-if)#ip policy route-map route_map_name fast-switched
C. R1(config-if)#ip route-cache policy
D. R1(config)#ip route-cache policy
|
| Answer: | C. R1(config-if)#ip route-cache policy
|
| Explanation: | To enable fast-switched policy-based routing we use the ip route-cache policy interface configuration command. |
|
| Question: | How do we change the next hop for routes coming from 192.168.1.1?
A. route-map Free-Tests permit 10 match ip address 10 set ip next-hop next_hop
B. route-map Free-Tests permit 10 match ip address 10 set ip next-hop next_hop
access-list 1 permit 192.168.1.1
C. route-map Free-Tests deny 10 match ip address 10 set ip next-hop next_hop
access-list 10 permit 192.168.1.1
D. route-map Free-Tests permit 10 match ip address 10 set ip next-hop next_hop
access-list 10 permit 192.168.1.1
|
| Answer: | D. route-map Free-Tests permit 10 match ip address 10 set ip next-hop next_hop
access-list 10 permit 192.168.1.1
|
| Explanation: | We use the set ip next hop command to alter the next hop for routes coming from 192.168.1.1, there must be an entry for the destination network of the packet in the routing table. |
|
| Question: | When there is no match in policy-based routing what happens to the packet?
A. It is discarded and the source receives an ICMP destination unreachable message.
B. It is routed to the Null0 interface and the source does not receive an ICMP destination unreachable message.
C. It is routed to the Null0 interface and the source receives an ICMP destination unreachable message.
D. It is send to the normal routing process to be routed to the destination.
|
| Answer: | D. It is send to the normal routing process to be routed to the destination.
|
| Explanation: | When the packet does not match any of the criteria of the route map it is send to the normal routing process to be routed by destination. |
|
| Question: | What is the difference between set ip default next-hop and set ip next-hop?
A. The ip default next-hop is used to set the default route and ip next-hop is just used to alter the path to the destination.
B. There is no difference between the two set commands.
C. IP default next-hop is used when there is no entry in the routing table for the destination network and ip next-hop there must be an entry for the destination network in the routing table.
D. IP next-hop is used when there is no entry in the routing table for the destination network and ip default next-hop there must be an entry for the destination network in the routing table.
|
| Answer: | C. IP default next-hop is used when there is no entry in the routing table for the destination network and ip next-hop there must be an entry for the destination network in the routing table.
|
| Explanation: | Set ip default next-hop>/b> is used when the routing table has no entry for the destination network of the packet. The set ip next-hop is used when there is an entry for the destination network in the routing table. Both must have the address of the adjacent router. |
|
| Question: | How can we control redistribution by only allowing routes that have a certain metric?
A. match metric
B. match route-type
C. match ip route-source
D. match tag
E. match ip metric
|
| Answer: | A. match metric
|
| Explanation: | The match metric will only redistribute routes with the metric specified. |
|
| Question: | When using route maps for redistribution which set commands can be used?
A. set ip next-hop
B. set metric
C. set ip tos
D. set level
E. set interface
|
| Answer: | B. set metric
D. set level
|
| Explanation: | The set commands used in redistribution are:
- set level
- set metric
- set metric-type
- set tag |
|
| Question: | How can we display a list of route maps used for policy-based routing on the routers interface?
A. show ip interface route-map
B. show route-map
C. show ip policy
D. show ip interface policy
|
| Answer: | C. show ip policy
|
| Explanation: | The show ip policy displays the route maps used for policy-based routing on the routers interface. |
|
| Question: | How can see the dynamic changes being made to the EIGRP routing table?
A. debug ip eigrp neighbors
B. debug eigrp route
C. debug ip eigrp
D. debug ip eigrp packet
|
| Answer: | C. debug ip eigrp
|
| Explanation: | When the debug ip eigrp command is issued it will default to debug ip eigrp route that will show the dynamic changes made to the routing table. |
|
| Question: | The administrative distance of IS-IS is?
A. 115
B. 110
C. 120
D. 90
E. 100
F. 160
|
| Answer: | A. 115
|
| Explanation: | | Source | Administrative Distance | | Connected Interface | 0 | | Static Route | 1 | | EIGRP Summary Route | 5 | | External BGP | 20 | | Internal EIGRP | 90 | | IGRP | 100 | | OSPF | 110 | | IS-IS | 115 | | RIP | 120 | | EGP | 140 | | On Demand Routing (ODR) | 160 | | External EIGRP | 170 | | Internal BGP | 200 | |
|
| Question: | When an IS-IS LSP arrives on a router with the OL bit set what is the significance of this?
A. The sending router had detected congestion on the link.
B. The sending router is a L1/L2 router.
C. The sending router has run out of memory for the link-state database.
D. The sending router has run out of CPU cycles to calculate the SPF algorithm.
|
| Answer: | C. The sending router has run out of memory for the link-state database.
|
| Explanation: | When a LSP has the OL (overload) bit set it means that the generating router has run out of memory for the link-state database. |
|
| Question: | Which routing loop avoidance technique is described? "The routing process will not advertise a route out of the interface through which that route was learned"
A. Split horizon with poison reverse
B. Poison reverse
C. Triggered update
D. Split horizon
|
| Answer: | D. Split horizon
|
| Explanation: | The split horizon rule state that the routing process will not advertise networks out of the interface through which those networks were learned. With poison reverse the routing process will advertise those networks but the metric will be set to infinite. |
|
| Question: | Using RIP, how do we configure R1 so that only R2 knows about the 192.168.5.x/24 network.
A. router rip network 192.168.1.0 network 192.168.5.0 neighbor 192.168.1.3
B. router rip passive-interface ethernet 1 network 192.168.1.0 network 192.168.5.0
C. router rip passive-interface ethernet 0 network 192.168.1.0 network 192.168.5.0
D. router rip passive-interface ethernet 0 network 192.168.1.0 network 192.168.5.0 neighbor 192.168.1.3
E. router rip passive-interface ethernet 1 network 192.168.1.0 network 192.168.5.0 neighbor 192.168.1.3
|
| Answer: | D. router rip passive-interface ethernet 0 network 192.168.1.0 network 192.168.5.0 neighbor 192.168.1.3
|
| Explanation: | By using the passive-interface router configuration command we block the sending of broadcast updates on the network. Because R2 needs to know about the 192.168.5.0/24 network we use the neighbor command to send out unicast updates to R2. R2 needs also to be configured in a similar way otherwise R3 would learn about 192.168.5.0/24 network via R2. |
|
| Question: | IGRP sends out periodic updates every _________ seconds?
A. 30
B. 180
C. 630
D. 120
E. 90
|
| Answer: | E. 90
|
| Explanation: | By default IGRP sends out periodic updates every 90 seconds. |
|
| Question: | How do we achieve load balancing across unequal paths in EIGRP?
A. traffic-share min
B. traffic-share max
C. variance
D. maximum-paths
|
| Answer: | C. variance
|
| Explanation: | The variance command can be used to load balance across unequal cost paths. Traffic-share min needs the across-interfaces keyword to have the same result otherwise it uses equal cost paths. |
|
| Question: | Hop count in IGRP is used for?
A. IGRP does not have a hop count
B. primary metric
C. secondary metric after the composite metric of bandwidth and delay
D. limit the diameter of the network
|
| Answer: | D. limit the diameter of the network
|
| Explanation: | By default the hop count in IGRP is 100 but it can be configured to 255 and is used to limit the diameter of the network. |
|
| Question: | The administrative distance of an EIGRP summary route is?
A. 120
B. 5
C. 90
D. 170
|
| Answer: | B. 5
|
| Explanation: | | Source | Administrative Distance | | Connected Interface | 0 | | Static Route | 1 | | EIGRP Summary Route | 5 | | External BGP | 20 | | Internal EIGRP | 90 | | IGRP | 100 | | OSPF | 110 | | IS-IS | 115 | | RIP | 120 | | EGP | 140 | | On Demand Routing (ODR) | 160 | | External EIGRP | 170 | | Internal BGP | 200 | |
|
| Question: | Which of the following routing protocols are interior routing protocols?
A. BGP
B. EGP
C. IS-IS
D. EIGRP
E. RIPv2
F. OSPF
|
| Answer: | C. IS-IS
D. EIGRP
E. RIPv2
F. OSPF
|
| Explanation: | RIPv1 & v2, OSPF, IGRP, EIGRP and IS-IS are considered interior routing protcols because they run inside the enterprise. Exterior routing protocols like BGP and EGP are/were used to exchange routing information between enterprises. |
|
| Question: | Link-state routing protocols reduce the network overhead by using?
A. By using broadcast updates.
B. By sending triggered updates that contain only the change instead of the entire routing table.
C. By sending of the entire routing table in each update.
D. By using multicast updates.
E. By not using hop count as a metric.
|
| Answer: | B. By sending triggered updates that contain only the change instead of the entire routing table.
D. By using multicast updates.
|
| Explanation: | Link-state routing protocols some of the following techniques to reduce the network overhead:
- use of multicast addressing
- sending of triggered updates
- infrequently sending network summaries
- not sending the entire routing table with every updated |
|
| Question: | BGP uses which metric?
A. hop count
B. composite metric
C. attributes
D. cost
|
| Answer: | C. attributes
|
| Explanation: | BGP has a complex metric called attributes by which traffic paths can be manipulated. |
|
| Question: | We want to reset all BGP sessions. How do we achieve this?
A. clear ip bgp reset
B. clear ip bgp *
C. clear ip route bgp
D. clear ip route *
|
| Answer: | B. clear ip bgp *
|
| Explanation: | The clear ip bgp * command will reset all BGP sessions. |
|
| Question: | A Level 2 IS-IS router can be compared to an OSPF ________ router.
A. area border
B. autonomous system boundary
C. backbone
D. internal
|
| Answer: | C. backbone
|
| Explanation: | IS-IS L1 routers can be compared to OSPF non-backbone internal routers.
IS-IS L2 routers can be compared to OSPF backbone routers.
IS-IS L1/L2 routers can be compared to OSPF area border routers. |
|
| Question: | Which of the following statements about IS-IS are true?
A. It does not support VLSM.
B. Hellos are sent every 10 seconds on all media.
C. Hellos are sent every 10 seconds on a broadcast network and every 30 seconds on a non-broadcast network.
D. It is a classless protocol
E. If there are no hellos for 40 seconds the neighbor is declared dead.
|
| Answer: | B. Hellos are sent every 10 seconds on all media.
D. It is a classless protocol
|
| Explanation: | IS-IS is a classless protocol that supports VLSM. Hellos are sent out every 10 seconds on all media (broadcast or non-broadcast) and a neighbor is declared dead after 30 seconds of silence. |
|
| Question: | Which of the following protocols support automatic summarization at the class boundary?
A. OPSF
B. IS-IS
C. RIP
D. IGRP
E. BGP
F. EIGRP
|
| Answer: | C. RIP
D. IGRP
E. BGP
F. EIGRP
|
| Explanation: | OSPF and IS-IS do not support automatic summarization at the class boundary but summarization can be configured manually. |
|
| Question: | In EIGRP hello packets are sent every ___________ seconds?
A. 30 on access links with a speed lower then T1
B. 10
C. 120 on access links with a speed lower then T1
D. 30
E. 5
F. 60 on access links with a speed lower then T1
|
| Answer: | E. 5
F. 60 on access links with a speed lower then T1
|
| Explanation: | On most networks EIGRP sends out hello packets via multicast every 5 seconds. On multipoint X.25, Frame-Relay or ATM interfaces with access speed lower or equal to T1, hello packets are send every 60 seconds using unicast.[on point-to-point subinterfaces hellos are send every 5 seconds] |
|
| Question: | Before the databases are synchronized and LSRs are being received the OSPF router goes through different states. What is the correct order?
A. Down,Init,Two-Way,Exstart,Exchange,Loading,Full
B. First,Second,Third,Fouth,Fifth,Sixth,Seventh
|
| Answer: | A. Down,Init,Two-Way,Exstart,Exchange,Loading,Full
|
| Explanation: | An OSPF router goes through the following states:
1 down state: sends out his own hello packet
2 init state: waits 4 times the hello interval to hear a reply
3 two-way state: the router sees it own ID in the list of neighbors, adjancency is formed
4 exstart state: neighbors determine the master/slave relationship
5 exchange state: both neighbors send out database description packets
6 loading state: the router wants more details using an LSR packet
7 full state: LSRs are received and databases are updated and synchronized, the neighbors are fully adjacent |
|
| Question: | After rebooting our router we want to view the state of our OSPF adjacencies. Which command do we use?
A. show ip protocols
B. show ip ospf neighbor
C. show ip ospf
D. show ip ospf database
|
| Answer: | B. show ip ospf neighbor
|
| Explanation: | R1# show ip ospf neighbor
ID Pri State Dead Time Address Interface
192.168.1.1 1 FULL/DROTHER 0:00:45 192.168.1.1 Ethernet0
172.16.4.15 1 FULL/DROTHER 0:00:45 172.16.4.15 Ethernet0
10.1.1.4 5 FULL/DR 0:00:44 192.168.1.3 Ethernet0
Show ip ospf neighbor will give a summary line for each neighbor. The show ip ospf interface command will also display the state of the interface running OSPF. |
|
| Question: | On which OSPF network topologies do we find a DR and BDR?
A. Point-to-point
B. Nonbroadcast multiaccess
C. Point-to-multipoint
D. Broadcast multiaccess
E. Point-to-point nonbroadcast
|
| Answer: | B. Nonbroadcast multiaccess
D. Broadcast multiaccess
|
| Explanation: | We find Designated Routers (DR) and Backup Designated Routers on broadcast multiaccess networks and nonbroadcast multiaccess networks. |
|
| Question: | The metric of OSPF is?
A. hop count
B. composite
C. cost
D. bandwidth
|
| Answer: | C. cost
|
| Explanation: | OSPF uses the cost as its metric, the cost is calculated by the following formula 10^8/bandwidth. |
|
| Question: | How can we set the RID on an OSPF router?
A. R1(config)#router-id x.x.x.x
B. R1(config)#interface loopback0 R1(config-if)#ip ospf router-id x.x.x.x
C. R1(config)#interface ethernet0 R1(config-if)#ip ospf router-id x.x.x.x
D. R1(config)#interface loopback0 R1(config-if)#ip address x.x.x.x y.y.y.y
E. R1(config)#router ospf 100 R1(config-router)#router-id x.x.x.x
|
| Answer: | D. R1(config)#interface loopback0 R1(config-if)#ip address x.x.x.x y.y.y.y
E. R1(config)#router ospf 100 R1(config-router)#router-id x.x.x.x
|
| Explanation: | If a loopback interface is configured on the router, the highest IP Address of the configured loopback interface(s) will be used as the router ID. We can also use the router-id command in router configuration mode. |
|
| Question: | On a frame-relay circuit the OSPF timers are?
A. dead timer 30 seconds
B. hello timer 40 seconds
C. hello timer 10 seconds
D. dead timer 40 seconds
E. dead timer 90 seconds
F. hello timer 30 seconds
G. dead timer 120 seconds
|
| Answer: | F. hello timer 30 seconds
G. dead timer 120 seconds
|
| Explanation: | Serial interfaces with frame relay encapsulation are nonbroadcast network types so the hello timer is 30 seconds and the dead timer is 120 seconds. |
|
| Question: | Which of the following OSPF network statements are the same?
A. network 192.168.1.0 area 1056
B. network 192.168.1.0 0.0.0.255 area 0.0.4.32
C. network 192.168.1.0 0.0.0.255 area 1.0.5.6
D. network 192.168.1.0 0.0.0.255 area 1056
E. network 192.168.1.0 0.0.0.255 area 0.0.10.56
|
| Answer: | B. network 192.168.1.0 0.0.0.255 area 0.0.4.32
D. network 192.168.1.0 0.0.0.255 area 1056
|
| Explanation: | The area parameter can be represented in either a decimal or dotted decimal format. The dotted decimal format should be read as one binary string, e.g. decimal 1056 = 00000000.00000000.00000100.00100000 = 0.0.4.32 in dotted decimal format. |
|
| Question: | How can we influence the metric of OSPF?
A. R1(config)#interface serial0 R1(config-if)#bandwidth 256k
B. R1(config)#interface serial0 R1(config-if)#ip ospf cost 10
C. R1(config)#router ospf 10 R1(config-router)#cost 10
D. R1(config)#interface serial0 R1(config-if)#bandwidth 256
E. R1(config)#router ospf 10 R1(config-router)#ip cost 10
|
| Answer: | B. R1(config)#interface serial0 R1(config-if)#ip ospf cost 10
D. R1(config)#interface serial0 R1(config-if)#bandwidth 256
|
| Explanation: | OSPF uses cost as a metric which is derived from the formula 10^8/bandwidth. Changing the bandwidth statement of an interface running OSPF will influence the metric. We can also use the ip ospf cost value interface configuration command to influence the cost. |
|
| Question: | How can we change the default cost calculation of OSPF?
A. R1(config)#ospf auto-cost reference-bandwidth 1000
B. R1(config-router)#ospf reference-bandwidth 1000
C. R1(config-if)#ospf reference-bandwidth 1000
D. R1(config)#ospf reference-bandwidth 1000
E. R1(config-router)#ospf auto-cost reference-bandwidth 1000
F. R1(config)#ospf auto-cost reference-bandwidth 1000
|
| Answer: | E. R1(config-router)#ospf auto-cost reference-bandwidth 1000
|
| Explanation: | Using the ospf auto-cost reference-bandwidth value router configuration command we can control how OSPF calculates default metrics for the interface. The value range is 1 to 4294967, the default is 100. |
|
| Question: | How do we configure OSPF on R1 in NBMA mode?
A. R1(config)#interface serial 0 R1(config-if)# ip address 192.168.1.2 255.255.255.0 R1(config-if)#encapsulation frame-relay R1(config-if)#ip ospf network non-broadcast R1(config)#router ospf 10 R1(config-router)#network 192.168.1.2 0.0.0.255 area 0 R1(config-router)#neighbor 192.168.1.4 R1(config-router)#neighbor 192.168.1.6
B. R1(config)#interface serial 0 R1(config-if)# ip address 192.168.1.2 255.255.255.0 R1(config-if)#encapsulation frame-relay R1(config-if)#ip ospf network non-broadcast R1(config)#router ospf 10 R1(config-router)#network 192.168.1.2 0.0.0.255 area 0
C. R1(config)#interface serial 0 R1(config-if)# ip address 192.168.1.2 255.255.255.0 R1(config-if)#encapsulation frame-relay R1(config-if)#ip ospf non-broadcast R1(config)#router ospf 10 R1(config-router)#network 192.168.1.2 0.0.0.255 area 0 R1(config-router)#neighbor 192.168.1.4 R1(config-router)#neighbor 192.168.1.6
D. R1(config)#interface serial 0 R1(config-if)# ip address 192.168.1.2 255.255.255.0 R1(config-if)#encapsulation frame-relay R1(config-if)#ip ospf network non-broadcast R1(config)#router ospf R1(config-router)#network 192.168.1.2 0.0.0.255 area 0 R1(config-router)#neighbor 192.168.1.4 R1(config-router)#neighbor 192.168.1.6
|
| Answer: | A. R1(config)#interface serial 0 R1(config-if)# ip address 192.168.1.2 255.255.255.0 R1(config-if)#encapsulation frame-relay R1(config-if)#ip ospf network non-broadcast R1(config)#router ospf 10 R1(config-router)#network 192.168.1.2 0.0.0.255 area 0 R1(config-router)#neighbor 192.168.1.4 R1(config-router)#neighbor 192.168.1.6
|
| Explanation: | The ip ospf network non-broadcast command is not necessary because this is the default used in nonbroadcast multiaccess environments. There is the need however to use the neighbor statements so adjacencies can be formed. |
|
| Question: | We want to know how many times the router has recalculated its routing table. Which command do we use?
A. show ip ospf
B. show ip ospf interface
C. show ip ospf database
D. show ip ospf neighbor
|
| Answer: | A. show ip ospf
|
| Explanation: | The show ip ospf command will show how many times the SPF algorithm has been executed.
R1#show ip ospf
Routing Process "ospf 10" with ID 10.1.1.1
Supports only single TOS(TOS0) routes
Supports opaque LSA
SPF schedule delay 5 secs, Hold time between two SPFs 10 secs
Minimum LSA interval 5 secs. Minimum LSA arrival 1 secs
LSA group pacing timer 100 secs
Interface flood pacing timer 55 msecs
Retransmission pacing timer 100 msecs
Number of external LSA 0. Checksum Sum 0x0
Number of opaque AS LSA 0. Checksum Sum 0x0
Number of DCbitless external and opaque AS LSA 0
Number of DoNotAge external and opaque AS LSA 0
Number of areas in this router is 2. 2 normal 0 stub 0 nssa
External flood list length 0
Area BACKBONE(0)
Number of interfaces in this area is 2
Area has message digest authentication
SPF algorithm executed 4 times
Area ranges are
Number of LSA 4. Checksum Sum 0x29BEB
Number of opaque link LSA 0. Checksum Sum 0x0
Number of DCbitless LSA 3
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
|
|
| Question: | How can make sure that a router will not become a DR or BDR?
A. ip ospf priority 0
B. ip ospf cost 0
C. no ip ospf priority
D. ip ospf priority 255
|
| Answer: | A. ip ospf priority 0
|
| Explanation: | The default priority is 1, this can be changed using the ip ospf priority command, setting the priority to 0 ensures that the router will not participate in DR or BDR elections. |
|
| Question: | Which of the following requirements have to be fulfilled in order to create a virtual link?
A. The transit area can be a stub area
B. The transit area can be a not-so-stubby area
C. The tranist area needs to have full routing information
D. The transit area can not be a stub area
E. The virtual link can be terminated on an interior router
|
| Answer: | C. The tranist area needs to have full routing information
D. The transit area can not be a stub area
|
| Explanation: | The area through which you configure the virtual link, known as a transit area, must have full routing information and this transit area cannot be a stub area. Virtual links are configured between ABRs and one of them must have a connection to the backbone. |
|
| Question: | If a route in the routing table is marked as O E1 we know the following about that route:
A. An LSA type 4 summary link in which the cost of the path to the ASBR is added to the external cost to reach the next-hop router outside the AS.
B. An LSA type 3 external link in which only the cost of path from the ASBR to the next-hop router outside the AS is considered.
C. An LSA type 4 external link in which only the cost of path from the ASBR to the next-hop router outside the AS is considered.
D. An LSA type 5 external link in which the cost of the path to the ASBR is added to the external cost to reach the next-hop router outside the AS.
E. An LSA type 5 external link in which only the cost of path from the ASBR to the next-hop router outside the AS is considered.
F. An LSA type 5 summary link in which the cost of the path to the ASBR is added to the external cost to reach the next-hop router outside the AS.
G. An LSA type 3 summary link in which the cost of the path to the ASBR is added to the external cost to reach the next-hop router outside the AS.
|
| Answer: | D. An LSA type 5 external link in which the cost of the path to the ASBR is added to the external cost to reach the next-hop router outside the AS.
|
| Explanation: | If the routing table entry is marked with O E1 it means that the LSA type 5 external route added the cost of the path to the ASBR to the external cost to reach the next-hop router outside the AS. |
|
| Question: | How can we change the default cost to the default route that is advertised into a stub area?
A. R1(config-if)#area x default-cost value
B. R1(config-if)#ip ospf default-cost value
C. R1(config-router)#area x default-cost value
D. R1(config-router)#area x cost value
|
| Answer: | C. R1(config-router)#area x default-cost value
|
| Explanation: | To define the cost of the default route generated and advertised by the ABR to the stub area we use the area area_id default-cost cost router configuration command. |
|
| Question: | In a NSSA which type of LSAs are not propgated into that area?
A. LSA type 5
B. LSA type 2
C. LSA type 3
D. LSA type 7
E. LSA type 4
F. LSA type 1
|
| Answer: | A. LSA type 5
E. LSA type 4
|
| Explanation: | In a NSSA (not-so-stubby area) there are no LSA type 4 and 5 propagated into or out of the area. |
|
| Question: | Which command would produce the following output?
Internet Address 172.16.2.2, Mask 255.255.255.0, Area 0.0.0.0
AS 1, Router ID 192.168.99.1, Network Type BROADCAST, Cost: 10
Transmit Delay is 1 sec, State OTHER, Priority 1
Designated Router id 192.168.25.1, Interface address 192.168.25.1
Backup Designated router id 192.168.4.8, Interface addr 192.168.4.8
Timer intervals configured, Hello 10, Dead 60, Wait 40, Retransmit 5
Hello due in 0:00:05
Neighbor Count is 8, Adjacent neighbor count is 2
Adjacent with neighbor 192.168.4.8 (Backup Designated Router)
Adjacent with neighbor 192.168.25.1 (Designated Router)
A. show ip ospf border-routers
B. show ip ospf database
C. show ip ospf interface
D. show ip ospf
|
| Answer: | C. show ip ospf interface
|
| Explanation: | R1# show ip ospf interface ethernet 0
Ethernet 0 is up, line protocol is up
Internet Address 172.16.2.2, Mask 255.255.255.0, Area 0.0.0.0
AS 1, Router ID 192.168.99.1, Network Type BROADCAST, Cost: 10
Transmit Delay is 1 sec, State OTHER, Priority 1
Designated Router id 192.168.25.1, Interface address 192.168.25.1
Backup Designated router id 192.168.4.8, Interface addr 192.168.4.8
Timer intervals configured, Hello 10, Dead 60, Wait 40, Retransmit 5
Hello due in 0:00:05
Neighbor Count is 8, Adjacent neighbor count is 2
Adjacent with neighbor 192.168.4.8 (Backup Designated Router)
Adjacent with neighbor 192.168.25.1 (Designated Router)
|
|
| Question: | On what type of router do we configure the summary address in OSPF?
A. Interior
B. ASBR
C. ABR
D. Backbone
|
| Answer: | B. ASBR
|
| Explanation: | The summary address is used to summarize the networks that will be advertised to the outside world. This is configured on the ASBR. |
|
| Question: | Following Ciscos design recommendations for OSPF what is the maximum amount of routers in an area?
A. 25
B. 100
C. 250
D. unlimited
E. 50
|
| Answer: | E. 50
|
| Explanation: | Ciscos design recommendations for OSPF stipulate the following:
- routers per area: 50
- neighbors per router: 60
- areas per router: 3
- a router may not be a DR or BDR for more then 1 LAN |
|
| Question: | What could prevent OSPF adjacencies to be formed?
A. misconfigured bandwidth statement
B. misconfigured ospf priority
C. no loopback interfaces configured
D. misconfigured MTU
E. misconfigured hello timer
|
| Answer: | D. misconfigured MTU
E. misconfigured hello timer
|
| Explanation: | Some common problems for adjacencies not being formed are misconfigured IP mask, MTU, interface hello timer, OSPF hello interval and OSPF dead interval. Also make sure that both neighbors are part of the same area and area type. |
|
| Question: | In the ISO address the area and system id of a system is IS-IS is described in the?
A. Subnetwork point of attachment
B. Network Entity Title
C. Network Selector
D. Host address
|
| Answer: | B. Network Entity Title
|
| Explanation: | The Network Entity Title (NET) describes both the area and system id of a system in the IS-IS network but excludes the Network Selector (NSEL), which defines the Network Service Access Point (NSAP) address of the system. |
|
| Question: | In ISO addressing which two fields are used for external routing?
A. High order DSP
B. Initial domain identifier (IDI)
C. System ID
D. Authority and format identifier (AFI)
E. Network selector (NSEL)
|
| Answer: | B. Initial domain identifier (IDI)
D. Authority and format identifier (AFI)
|
| Explanation: | The IDP part of an ISO address is used for external routing and is issued by the ISO. It contains 2 parts, the authority and format identifier (AFI) and the initial domain identifier (IDI). |
|
| Question: | Which statements are true regarding ISO addressing?
A. All level 1 routers must have a system ID that is unique for the entire domain.
B. All level 1 routers must have a system ID that is unique for the entire area.
C. The area address must be the same for all routers in the same domain.
D. All level 2 routers must have a system ID that is unique for the entire area.
E. All level 2 routers must have a system ID that is unique for the entire domain.
F. The ISO address is assigned to the interface.
|
| Answer: | B. All level 1 routers must have a system ID that is unique for the entire area.
E. All level 2 routers must have a system ID that is unique for the entire domain.
|
| Explanation: | Some of the rules for ISO addressing:
- the ISO address is assigned to the system, not to the interface
- the router has one NET address, with a limit of 3 per area in multiarea Intergrated IS-IS
- when multiple NETs are configured on the same router they must have the same system id
- the area address must be the same for all routers in the same area
- Level 2 routers must have a system ID that is unique for the entire domain
- Level 1 routers must have a system ID that is unique for the entire area
- The system ID length must be the same for ISs and ESs within a routing domain |
|
| Question: | Which IS-IS packet is used to request individual LSPs and to acknowledge receipt of those?
A. CSNP
B. LAN Level 1
C. Level 1 LSP
D. LAN Level 2
E. PSNP
F. Level 2 LSP
|
| Answer: | E. PSNP
|
| Explanation: | A PSNP or Partial Sequence Number Packet is used to request individual LSPs and to acknowledge receipts of these LSPs. |
|
| Question: | When configuring IS-IS on a Cisco router it is which IS-IS router by default?
A. Level 1-2
B. Level 2
C. No defaults, this needs to be configured.
D. Level 1
|
| Answer: | A. Level 1-2
|
| Explanation: | The IS-IS Level 1-2 router configuration is the default configuration on Cisco routers. |
|
| Question: | Which of the following are IS-IS network types?
A. Point-to-multipoint
B. Point-to-multipoint nonbroadcast
C. Broadcast
D. Point-to-point
E. NonBroadcast MultiAccess
|
| Answer: | C. Broadcast
D. Point-to-point
|
| Explanation: | IS-IS defines 2 network types, broadcast subnetworks and point-to-point networks. |
|
| Question: | Which fields in the IS-IS LAN Hello packet are not in the Point-to-Point Hello packet?
A. Holding time
B. Local Circuit ID
C. Circuit type
D. Priority
E. LAN ID
|
| Answer: | D. Priority
E. LAN ID
|
| Explanation: | The common fields in both Hello packets are:
- Fixed Integrated IS-IS header
- Circuit type
- Source ID
- Holding time
- Packet length
In Point-to-point Hello packets we have an additional Local Circuit ID field. In LAN Hello packets there are the Priority and LAN ID fields. |
|
| Question: | TLV code 129 or Protocols Supported are used by which PDU?
A. LSP Level 1
B. SNP
C. LSP Level 2
D. Hello
E. LSP Level 1 and 2
|
| Answer: | D. Hello
|
| Explanation: | TLV code 129, Protocols Supported is used by the Hello PDU and states the protocols that the transmitting router supports, i.e. CLNS only, IP only or both. |
|
| Question: | In order to form IS-IS adjacencies which of the following have to match?
A. Hold down timer
B. Dead Interval timer
C. System ID
D. Bandwidth
E. MTU
|
| Answer: | E. MTU
|
| Explanation: | In order to form and maintain an adjacency the interfaces have to agree on the following:
- MTU size
- Same level of routing, either Level 1 or Level 2
- If they are Level 1 routers they must be in the same area
- In order for a Level 1 router to communicate with a Level 2 router or vice versa they need to form an adjacency with a Level 1-2 router
- System ID must be unique for each router
- Authentication must be identical on both routers if configured |
|
| Question: | ISO 10589 defines the metric for Integrated IS-IS. Which of the following are part of that?
A. Bandwidth
B. Error
C. Reliability
D. Hop
E. Delay
F. Attribute
|
| Answer: | B. Error
E. Delay
|
| Explanation: | Integrated IS-IS has 4 metrics defined by ISO 10589:
- Default
- Delay
- Expense
- Error |
|
| Question: | A DIS sends out Hello Packets every __________ seconds?
A. 3
B. 30
C. 45
D. 15
E. 3.3
F. 10
|
| Answer: | E. 3.3
|
| Explanation: | A DIS sends out Hello packets every 3.3 seconds to maintain the adjacencies with the other routers. Other routers send out Hello Packets every 10 seconds. |
|
| Question: | When electing a DIS and the priorities are all equal what will be used to elect the DIS?
A. The highest numeric SNPA
B. The lowest numeric SNPA
C. The highest numeric IP Address
D. The lowest numeric IP Address
E. The highest value in the TLV
F. The lowest value in the TLV
|
| Answer: | A. The highest numeric SNPA
|
| Explanation: | A DIS election is based on priority (default is 64) if all priorities are the default value then the highest SNPA (Subnetwork Point of Attachment), the data-link address will determine the DIS. |
|
| Question: | When a new router is with a higher priority appears on a IS-IS network what will happen to the DIS?
A. The new router will become to new DIS after a new election.
B. The new router will become to new DIS and the old DIS becomes a backup DIS.
C. Nothing will happen and the DIS remains the same.
D. The new router will become a backup DIS and will take over the role of the current DIS when it fails.
|
| Answer: | A. The new router will become to new DIS after a new election.
|
| Explanation: | When a DIS has a problem or a new router with a higher priority comes online a new DIS is elected in the place of the old DIS. |
|
| Question: | Which fields in an LSP packet determine if the LSP is newer then the one in the database?
A. Checksum
B. Priority
C. Sequence number
D. Version
E. Holding time
F. Remaining lifetime
G. LAN ID
|
| Answer: | A. Checksum
C. Sequence number
F. Remaining lifetime
|
| Explanation: | The tree fields used in an LSP to determine if the LSP is newer then the one in the database are:
- Remaining lifetime
- Sequence number
- Checksum |
|
| Question: | At with stage in the IS-IS routing process does the Dijkstra algorithm run?
A. Update
B. Forwarding
C. Receive
D. Decision
|
| Answer: | D. Decision
|
| Explanation: | During the decision stage of the IS-IS routing process the Dijkstra algorithm is executed to create the shortest path tree to all destinations. |
|
| Question: | How do we change the entire router to be Level 1 only IS-IS router?
A. router isis is-type level-1
B. router isis isis circuit-type level-1
C. interface ethernet0 isis circuit-type level-1
D. interface ethernet0 is-type level-1
|
| Answer: | A. router isis is-type level-1
|
| Explanation: | We use the is-type router configuration command to change the routing level the IS-IS routing process for the entire router or for the instance of IS-IS if there are more then 1 instances running. |
|
| Question: | Which of the 4 metrics defined by ISO 10589 for Integrated IS-IS is supported by Cisco and what is its value?
A. Delay
B. 64
C. Default
D. 15
E. Error
F. 100
G. 10
H. Expense
|
| Answer: | C. Default
G. 10
|
| Explanation: | The default or cost is the only out of the 4 metrics of IS-IS supported by Cisco. Its default value is 10 on all interfaces. |
|
| Question: | In Integrated IS-IS, TLV stands for?
A. Length
B. Value
C. Type
D. Version
E. Lifetime
F. Local ciruict ID
G. Length indication
H. Packet length
I. Time
|
| Answer: | A. Length
B. Value
C. Type
|
| Explanation: | The structure of the TLV is:
- Type or Code, the type of TLV that identifies it and the characteristics that are related to it
- Length, the length of the following field
- Value, IP routes, IS-IS neighbors or authentication |
|
| Question: | We want to summarize our IP routes for Integrated IS-IS. How do we configure this?
A. interface ethernet 0 ip router isis summary-address ip address mask
B. interface ethernet 0 ip router isis summary-address address mask
C. router isis summary-address ip address mask
D. router isis summary-address address mask
|
| Answer: | D. router isis summary-address address mask
|
| Explanation: | To create IP routes summarization for Integrated IS-IS we use the summary-address address mask router configuration command. |
|
| Question: | Which of the following IP Addresses is a Class C Private network address?
A. 11000000.10101000.00010001.00001001
B. 11000000.10101010.00010001.00001001
C. 11000000.11101000.00010001.00001001
D. 11000000.10101001.00010001.00001001
E. 10100000.10101000.00010001.00001001
|
| Answer: | A. 11000000.10101000.00010001.00001001
|
| Explanation: | RFC1918 specifies the allocation of IP Addresses for Private Internets.
Class A 10.0.0.0 - 10.255.255.255 (10/8 prefix)
Class B 172.16.0.0 - 172.31.255.255 (172.16/12 prefix)
Class C 192.168.0.0 - 192.168.255.255 (192.168/16 prefix)
or in binary (only the first 2 otctets are represented)
Class A 0000 1010.0000 0000
Class B 1010 1100.0001 0000
Class C 1100 0000.1010 1000
|
|
| Question: | In OSPF the DRs use which IP Address to exchange link-state information?
A. 224.0.0.5
B. 224.0.0.6
C. 224.0.0.9
D. 224.0.0.10
|
| Answer: | A. 224.0.0.5
|
| Explanation: | OSPF uses 224.0.0.5 (all OSPF routers) to exchange link-state information and listens to 224.0.0.6 (all OSPF designated routers) to receive multicast updates from DRothers.
More reserverd multicast addresses can be found here: http://www.iana.org/assignments/multicast-addresses |
|
| Question: | We want to advertise only a default route via EIGRP. How do we achieve this?
A. R1(config)#router EIGRP 1000 R1(config-router)#neighbor 172.16.1.25 default-originate always
B. R1(config)#router EIGRP 1000 R1(config-router)#ip summary-address eigrp 1000 0.0.0.0 0.0.0.0
C. R1(config)#interface serial0 R1(config-if)#ip summary-address eigrp 1000 0.0.0.0 0.0.0.0
D. R1(config)#ip summary-address eigrp 1000 0.0.0.0 0.0.0.0
|
| Answer: | C. R1(config)#interface serial0 R1(config-if)#ip summary-address eigrp 1000 0.0.0.0 0.0.0.0
|
| Explanation: | To advertise just a default route and suppress all other routing updates we use the ip summary-address eigrp as_number 0.0.0.0 0.0.0.0 command in interface configuration mode. Replacing 0.0.0.0 0.0.0.0 with a summary address and network mask will advertise that summary route. We also need to disable the automatic summarization with the no auto-summary router configuration command. |
|
| Question: | EIGRP uses the following tables?
A. Route/Forwarding table
B. Cost table
C. Topology table
D. Link-state table
E. Neighbor table
F. EIGRP table
|
| Answer: | A. Route/Forwarding table
C. Topology table
E. Neighbor table
|
| Explanation: | The neighbor table contains every formed adjacency. The topology table is where all the learned routes are kept. The route/forwarding table contains the lowest composite metric routes. |
|
| Question: | When using autoconfiguration with IPv6 what are the minimum requirements?
A. R1(config-if)#ipv6 unicast-routing
B. R1(config)#ipv6 unicast-routing R1(config-router)#ipv6 enable
C. R1(config)#ipv6 unicast-routing
D. R1(config)#ipv6 unicast-routing R1(config)#interface type R1(config-if)#ipv6 enable
|
| Answer: | D. R1(config)#ipv6 unicast-routing R1(config)#interface type R1(config-if)#ipv6 enable
|
| Explanation: | When a node initializes it generates a link-local address for that interface. The link-local address is the interface?s identifier concatenated with the well-known link-local prefix FE80:: The rightmost zeros of the link-local prefix are replaced with the interface ID.
Example, link-local prefix FE80:0:0:0:0:0:0:0 and interface ID 200:CFF:FE0A.2C51 form link-local address FE80:0:0:0:200:CFF:FE0A.2C51 The node then initiates the duplicate address detection progress and if no duplicate address exists then the node assigns the generated local-link address to the interface. |
|
| Question: | We want to redistribute our RIP routes into OSPF. What is the correct configuration to achieve this?
A. R1(config)#router rip R1(config-router)#redistribute ospf
B. R1(config)#redistribute rip ospf
C. R1(config)#router ospf 100 R1(config-router)#redistribute rip subnets
D. R1(config)#router ospf R1(config-router)#redistribute rip subnets
|
| Answer: | C. R1(config)#router ospf 100 R1(config-router)#redistribute rip subnets
|
| Explanation: | The redistribute command allows to inject routes from one routing protocol into another. The subnets keyword is needed to redistribute subnetted routes otherwise only non-subnetted routes are redistributed. |
|
| Question: | What happens when a Designated Router fails in an OSPF network?
A. An election is held between all the Backup Designated Routers and the Backup Designated Router with the lowest priority becomes the Designated Router
B. The Backup Designated Router takes over the role of Designated Router even if the Designated Router comes back online and a new Backup Designated Router is elected
C. The Backup Designated Router takes over the role of Designated Router but seizes to have this role when the original Designated Router comes back online and a new Backup Designated Router is elected
D. An election is held between all the Backup Designated Routers and the Backup Designated Router with the highest priority becomes the Designated Router
|
| Answer: | B. The Backup Designated Router takes over the role of Designated Router even if the Designated Router comes back online and a new Backup Designated Router is elected
|
| Explanation: | A significant problem with the Designated Router (DR) scheme is that if the DR fails, a new DR must be elected. New adjacencies must be established, and all routers on the network must synchronize their databases with the new DR (part of the adjacency-building process). While all this is happening, the network is unavailable for transit packets.
To prevent this problem, a Backup Designated Router (BDR) is elected in addition to the DR. All routers form adjacencies not only with the DR but also with the BDR. The DR and BDR also become adjacent with each other. If the DR fails, the BDR becomes the new DR. Because the other routers on the network are already adjacent with the BDR, network unavailability is minimized.
When an OSPF router becomes active and discovers its neighbours, it checks for an active DR and BDR. If a DR and BDR exist, the router accepts them. If there is no BDR, an election is held in which the router with the highest priority becomes the BDR. If more than one router has the same priority, the one with the numerically highest Router ID wins. If there is no active DR, the BDR is promoted to DR and a new election is held for the BDR.
It should be noted that the priority can influence an election, but will not override an active DR or BDR. That is, if a router with a higher priority becomes active after a DR and BDR have been elected, the new router will not replace either of them. So the first two DR-eligible routers to initialize on a multi-access network will become the DR and BDR. |
|
| Question: | What type of LSAs are not flooded into a totally stubby area?
A. LSA type 2
B. LSA type 1
C. LSA type 5
D. LSA type 4
|
| Answer: | C. LSA type 5
D. LSA type 4
|
| Explanation: | Because totally stubby areas use a default route to all destinations (external to the AS and area) the ABR will block LSA type 4 and 5 but also all summary LSAs with the exception of a single type 3 LSA to advertise the default route. |
|
| Question: | What type of LSA are used to advertise routes that have been redistributed into OSPF?
A. LSA type 5
B. LSA type 1
C. LSA type 3
D. LSA type 7
|
| Answer: | A. LSA type 5
|
| Explanation: | LSA type 5 or Autonomous System External LSAs are used to advertise routes that have been redistributed into OSPF. They are flooded throughout the entire system except for stub, totally stub and not-so-stubby areas. |
|
| Question: | How can we influence the DR and BDR election?
A. R1(config)#interface ethernet0 R1(config-if)#ip priority 220
B. R1(config)#interface ethernet0 R1(config-if)#ip ospf priority 0
C. R1(config)#router ospf 10 R1(config-router)#priority 220
D. R1(config)#interface ethernet0 R1(config-if)#ip ospf priority 220
|
| Answer: | D. R1(config)#interface ethernet0 R1(config-if)#ip ospf priority 220
|
| Explanation: | The ip ospf priority command will set a value to the interface that will be used when the DR and BDR is elected. The highest priority will win the election, in case of a tie the highest RID will win. |
|
| Question: | What command do we use to view the state of adjacencies formed with other routers in OSPF?
A. Show ip ospf neighbor
B. Show ip ospf detail
C. Show ip ospf database
D. Show ip ospf database summary
|
| Answer: | A. Show ip ospf neighbor
|
| Explanation: | The show ip ospf neighbor command shows the operational status of all OSPF neighbors (adjacencies). |
|
| Question: | A route external to the OSPF AS that does not take the cost to the ASBR into account is entered in the routing table with the following code?
A. O E2
B. O E1
C. O
D. O IA
|
| Answer: | A. O E2
|
| Explanation: | Type 2 external paths (E2) are routes external to the OPSF AS and do no take the cost into account of the path to the ASBR. |
|
| Question: | We want to inject a summary route, from other OSPF areas, into the backbone area 0 from an ABR. What command do we use?
A. summary-address network networkmask
B. area network networkmask
C. summary-route network networkmask
D. area x range network networkmask
|
| Answer: | D. area x range network networkmask
|
| Explanation: | To inject a summary route of other OSPF areas via the ABR into the backbone we use the area area_id range network_address network_mask router configuration command on the ABR. |
|
| Question: | A network LSA originates from which router?
A. DR
B. BDR
C. ABR
D. ASBR
|
| Answer: | A. DR
|
| Explanation: | Network LSAs (type 2) originate from the DR on every multi-access network and list all attached routers including it self. |
|
| Question: | Which of the following are well-known mandatory attributes?
A. Atomic_Aggregate
B. Multi_Exit_Disc
C. Local_Pref
D. Next_hop
E. AS_path
F. Aggregator
|
| Answer: | D. Next_hop
E. AS_path
|
| Explanation: | The 3 well-known mandatory attributes are:
- Origin
- AS_Path
- Next_Hop
|
|
| Question: | We want to configure EIGRP on R1 but E1 is not allowed to participate in the EIGRP process. How do we achieve this?
A. R1(config)#router eigrp 10 R1(config-router)#network 10.1.1.1 R1(config-router)#network 192.168.1.0
B. R1(config)#router eigrp 10 R1(config-router)#network 10.1.1.1 R1(config-router)#network 192.168.1.0 R1(config)#interface ethernet 1 R1(config-if)#ip eigrp passive
C. R1(config)#router eigrp 10 R1(config-router)#network 10.1.1.1 0.0.0.0 R1(config-router)#network 192.168.1.0
D. R1(config)#router eigrp 10 R1(config-router)#network 10.1.1.1 0.0.0.0 as 10 R1(config-router)#network 192.168.1.0
|
| Answer: | C. R1(config)#router eigrp 10 R1(config-router)#network 10.1.1.1 0.0.0.0 R1(config-router)#network 192.168.1.0
|
| Explanation: | Since the release of IOS 12.01(T) the network statement was given the ability to use wildcard masks like OSPF. Prior to that IOS release the router (IOS) would correct the address to the major classful network number, in this case 10.0.0.0 which would include ethernet 1. In earlier releases this would be achieved with the passive-interface router configuration command. |
|
| Question: | Which of the following statements are true about route reflectors?
A. If a route is received from an eBGP peer advertise the route to all clients but not to the non clients
B. If a route is received from a non client, drop the route
C. If a route is received from a client, advertise the route to the other clients and non clients
D. if a route is received from a non client advertise the route to all the clients
|
| Answer: | C. If a route is received from a client, advertise the route to the other clients and non clients
D. if a route is received from a non client advertise the route to all the clients
|
| Explanation: | Route reflectors use the following rules:
- if the route is received from a non client peer then advertise that route to all the clients
- if the route is received from a client peer then advertise the route to all non clients and client peers
- if the route is received from an external BGP peer advertise the route to all the client and non client peers
|
|
| Question: | Which of the following statements are true about BGP?
A. BGP is described in RFC 1771
B. BGP uses TCP port 179
C. BGP does not support VLSM
D. Is a distance vector protocol.
E. BGP is a link-state protocol
|
| Answer: | A. BGP is described in RFC 1771
B. BGP uses TCP port 179
|
| Explanation: | BGP is described in RFC 1771 (http://www.ietf.org/rfc/1771rfc.txt) and uses TCP port 179 as its transport protocol. |
|
| Question: | Which of the following fields belong to the OPEN message in BGP?
A. Version
B. Network Layer Reachability Information
C. Autonomous system number
D. Hello time
E. Path attributes
|
| Answer: | A. Version
C. Autonomous system number
|
| Explanation: | The BGP OPEN message contains the following fields:
- BGP version number
- Autonomous system number
- Hold time
- BGP identifier
- Optional parameters
|
|
| Question: | In which order are the following six decisions evaluated during the BGP decision process?
A. First,Second,Third,Fouth,Fifth,Sixth
B. Next Hop Availability,Highest Administrative Weight,Highest Local Prefernece,Shortest AS Path,Lowest MED,External over Internal BGP
|
| Answer: | B. Next Hop Availability,Highest Administrative Weight,Highest Local Prefernece,Shortest AS Path,Lowest MED,External over Internal BGP
|
| Explanation: | The BGP decision process follows the following steps:
- if the next hop is unavailable ignore the route
- prefer the path with the highest administrative weight (Cisco proprietary)
- if the weights are equal prefer the route with the highest local preference
- if the local preferences are equal prefer the route with the shortest AS_Path
- if the AS_Paths are equal prefer the route with the lowest origin type
- if the origin type is the same prefer the route with the lowest MED
- if the MED is equal prefer external BGP routes over internal BGP routes
- if everything is still equal prefer the route with the shortest path to the BGP Next_Hop, i.e. the route with the lowest IGP metric to the next-hop router
- the last step is prefer the route advertised by the router with the lowest RID |
|
| Question: | When configuring BGP we want to use loopback0 as the interface to establish the peering sessions. How can we achieve this?
A. neighbor 10.1.1.1 remote-as 1 neighbor 10.1.1.1 update-interface loopback0
B. neighbor 10.1.1.1 remote-as 1 neighbor 10.1.1.1 peer loopback0
C. neighbor 10.1.1.1 remote-as 1 neighbor 10.1.1.1 update-source loopback0
D. neighbor 10.1.1.1 remote-as 1 neighbor 10.1.1.1 update-peer loopback0
|
| Answer: | C. neighbor 10.1.1.1 remote-as 1 neighbor 10.1.1.1 update-source loopback0
|
| Explanation: | The update-source command used in combination with the neighbor command lets us choose the interface we will use as a source IP address for the peering session with that neighbor. |
|
| Question: | What is the origin code for a route originated on a BGP router?
A. 0
B. 1
C. 2
D. 3
|
| Answer: | A. 0
|
| Explanation: | Origin Code Origin Code name Description
0 IGP Route originated from a BGP router.
1 EGP Route originated from an EGP (not eBGP)
2 Incomplete Route originated from a routing process
other then BGP via redistribution . |
|
| Question: | The default BGP holdtime for a session is?
A. 120 seconds
B. 180 seconds
C. 60 seconds
D. 240 seconds
|
| Answer: | B. 180 seconds
|
| Explanation: | The default BGP holdtime, sent in the open message, is 180 seconds. |
|
| Question: | On a broadcast multiaccess OSPF network Hellos are send every _______ ?
A. 40 seconds
B. 90 seconds
C. 30 minutes
D. 10 seconds
E. 60 seconds
|
| Answer: | D. 10 seconds
|
| Explanation: | Hellos are send periodically every 10 seconds (default) on a broadcast multiaccess media. |
|
| Question: | When using OSPF the router is in __________ state when neighbors are established?
A. two-way
B. full
C. exchange
D. init
E. loading
|
| Answer: | A. two-way
|
| Explanation: | In the two-way state the router sees its own router ID in the list of neighbors and neighbor relationships (adjacencies) are established. |
|
| Question: | An IPv6 address that is within the same site but might be on a different network is a ____________ address?
A. Site local
B. Area local
C. Link local
D. Network local
|
| Answer: | A. Site local
|
| Explanation: | A site local is unicast address that is within the same site but it could be on a different network. |
|
| Question: | Where in the Cisco hierarchical design would you find access lists?
A. Core layer
B. Network layer
C. Transport layer
D. Distribution layer
E. Access layer
|
| Answer: | D. Distribution layer
|
| Explanation: | The distribution layer is responsible for determining access across the backbone by filtering out unnecessary resource updates and selectively granting access to users and departments via access lists. |
|
| Question: | In the show ip bgp output what does a status code of d means?
A. The route is being distibuted amongst the iBGP peers.
B. The route is dampened.
C. The route is deleted.
D. The route is deleted from the BGP table.
|
| Answer: | B. The route is dampened.
|
| Explanation: | If a route in the BGP table has a status code of d it means that this entry has been dampened. |
|
| Question: | How do we apply policy-based routing to packets generated by the router?
A. R1(config-router)#ip local policy route-map route_map_name
B. R1(config-if)#ip local policy route-map route_map_name
C. R1(config)#ip local policy route-map route_map_name
D. R1(config)#ip policy route-map route_map_name
E. R1(config-if)#ip policy route-map route_map_name local
|
| Answer: | C. R1(config)#ip local policy route-map route_map_name
|
| Explanation: | To apply policy-based routing on packets generated by the router we use the ip local policy route-map route_map_name global configuration command. |
|
| Question: | Which of the following statements are true when you configure OSPF point-to-multipoint?
A. Each spoke in the network has its own subnet.
B. There is a DR/BDR election.
C. The network has to be fully meshed.
D. The network uses 1 subnet.
E. There is no DR/BDR election.
|
| Answer: | D. The network uses 1 subnet.
E. There is no DR/BDR election.
|
| Explanation: | When using point-to-mulitpoint OSPF configuration the network is in one subnet and there is no DR/BDR election. |
|
| Question: | Integrated IS-IS supports which protocols?
A. IPX
B. CLNP
C. AppleTalk
D. IP
E. DecNet
|
| Answer: | B. CLNP
D. IP
|
| Explanation: | Integrated IS-IS supports IP and CLNP. |
|
| Question: | What is the range of multicast addresses in IPv6?
A. FF00::/8 to FFAA::/8
B. FF00::/16 to FFAA::16
C. FF00::/8 to FF99::/8
D. FF00::/16 to FFFF::/16
E. FF00::/8 to FFFF::/8
|
| Answer: | E. FF00::/8 to FFFF::/8
|
| Explanation: | The multicast address range in IPv6 is FF00::/8 to FFFF::/8 because all IPv6 multicast addresses have the first 8 bits set to 1, 1111 1111 or FF. |
|
| Question: | Which command will display the DoNotAge external LSA?
A. Show ip ospf process_id
B. Show ip ospf interface
C. Show ip ospf database
D. Show ospf database
E. Show ip ospf neighbor
|
| Answer: | A. Show ip ospf process_id
|
| Explanation: | The show ip ospf process_id command will display the DoNotAge External LSA used with OSPF demand circuits, like ISDN. |
|
| Question: | OSPF supports which forms of authentication?
A. Radius
B. Kerberos
C. NTLM
D. Simple passwords
E. MD5
|
| Answer: | D. Simple passwords
E. MD5
|
| Explanation: | OSPF supports simple passwords and MD5 authentication to authenticate packets send between neighbors. |
|
| Question: | How do we prevent OSPF Hellos being sent out of the ethernet interface of R1?
A. R1(config)#router ospf 10 R1(config-router)#passive-interface ethernet 0
B. R1(config-if)#passive-interface ospf
C. R1(config)#passive-interface ethernet 0
D. R1(config)#router ospf 10 R1(config-router)#passive interface ethernet 0
|
| Answer: | A. R1(config)#router ospf 10 R1(config-router)#passive-interface ethernet 0
|
| Explanation: | To surpress OSPF or EIGRP Hello packets or RIP updates we can use the passive-interface interface router configuration command. |
|
| Question: | How do we change the percentage of bandwidth used by EIGRP for its traffic?
A. R1(config)#router eigrp 10 R1(config-router)#ip bandwidth-percent percent interface
B. R1(config)#ip bandwidth-percent eigrp eigrp_as percent
C. R1(config)#interface ethernet 0 R1(config-if)#ip bandwidth-percent eigrp eigrp_as percent
D. R1(config)#interface ethernet 0 R1(config-if)#ip bandwidth-percent eigrp_as percent
|
| Answer: | C. R1(config)#interface ethernet 0 R1(config-if)#ip bandwidth-percent eigrp eigrp_as percent
|
| Explanation: | To change the percentage of bandwidth used by EIGRP for its traffic we use the ip bandwidth-percent eigrp eigrp_as percent interface configuration command. |
|
| Question: | How can we view the content of each LSP sent by IS-IS?
A. show isis database lspid
B. show isis database
C. show isis database detail
D. show isis database summary
|
| Answer: | C. show isis database detail
|
| Explanation: | The show isis area database command with the keyword detail added will show the content of each LSP. |
|
| Question: | What is the difference between a NET and a NSAP address?
A. A NSAP address is the address of the host where the value of the NSEL is set to 0x00.
B. A NET address is the address of the host where the value of the NSEL is set to 0x01.
C. A NET address is the address of the host where the value of the NSEL is set to 0x00.
D. A NET address is the address of the host where the value of the AFI is set to 49.
|
| Answer: | C. A NET address is the address of the host where the value of the NSEL is set to 0x00.
|
| Explanation: | A NET address is the address of the host where the value of the NSEL is set to 0x00. The NSAP is the full ISO address, the NSEL field specifies the upper-layer protocol. |
|
| Question: | Which command will tell us what type of OSPF router the router is we are connected to?
A. show ip ospf interface
B. show ip ospf neighbor
C. show ip ospf database
D. show ip ospf process_id
|
| Answer: | D. show ip ospf process_id
|
| Explanation: | The show ip ospf process_id will display the specific type of OSPF router, e.g. It is an internal router. |
|
| Question: | When a BGP AS is broken up into smaller sub-ASs we call those?
A. Route Reflectors
B. Private AS
C. Peer Group
D. Domain
E. Confederations
|
| Answer: | E. Confederations
|
| Explanation: | When an AS is divided in smaller sub-ASs we call it a confederation. Inside each confederation the rules of iBGP apply, e.g. they must be fully meshed. |
|
