RIP isn't exactly the most complex routing protocol on the CCNA exam, but that makes it easy to overlook some of the important details you must keep in mind in order to pass the exam! To help you review for the exam, here are just a few of those details!
RIP’s default behavior is to send version 1 updates, but to accept both version 1 and 2 routing updates.
R2(config)#router rip
R2(config-router)#net 172.16.0.0
R2(config-router)#^Z
R2#show ip protocols
Routing Protocol is "rip"
Sending updates every 30 seconds, next due in 6 seconds
Invalid after 180 seconds, hold down 180, flushed after 240
Outgoing update filter list for all interfaces is
Incoming update filter list for all interfaces is
Redistributing: rip
Default version control: send version 1, receive any version
Interface Send Recv Key-chain
Serial0 1 1 2
By default, RIP v2 autosummarizes routing updates sent across classful network boundaries. To disable this behavior, run no auto-summary under the RIP process.
R1#conf t
R1(config)#router rip
R1(config-router)#version 2
R1(config-router)#no auto-summary
You do not specify a subnet mask or wildcard mask when configuring RIP – just the classful network, even if you’re running RIP v2.
R1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#router rip
R1(config-router)#version 2
R1(config-router)#no auto-summary
R1(config-router)#network 172.10.0.0 ?
Debug ip rip displays the routing updates and metrics as the advertisements are sent and requested. To see this in action without waiting for the next regularly scheduled update, run clear ip route *.
R1#debug ip rip
RIP protocol debugging is on
R1#clear ip route *
01:16:54: RIP: sending v1 update to 255.255.255.255 via Loopback1 (1.1.1.1)
01:16:54: network 2.0.0.0, metric 2
01:16:54: network 3.0.0.0, metric 2
01:16:54: network 172.16.0.0, metric 1
01:16:54: network 10.0.0.0, metric 2
01:16:54: RIP: sending v1 update to 255.255.255.255 via Serial0 (172.16.123.1)
01:16:54: subnet 172.16.123.0, metric 1
01:16:54: network 1.0.0.0, metric 1
01:16:54: network 2.0.0.0, metric 2
01:16:54: network 3.0.0.0, metric 2
01:16:54: network 10.0.0.0, metric 2
To see only the routes discovered by a routing protocol, run show ip route followed by the name of the protocol:
R1#show ip route rip
R 2.0.0.0/8 [120/1] via 172.16.123.2, 00:00:26, Serial0
R 3.0.0.0/8 [120/1] via 172.16.13.2, 00:00:09, Serial1
[120/1] via 172.16.123.3, 00:00:09, Serial0
R 10.0.0.0/8 [120/1] via 172.16.13.2, 00:00:09, Serial1
[120/1] via 172.16.123.3, 00:00:09, Serial0
[120/1] via 172.16.123.2, 00:00:26, Serial0
And don't forget - to turn off all currently running debugs, run undebug all.
R1#undebug all
All possible debugging has been turned off
Don't overlook RIP and IGRP when it comes to the CCNA exam. OSPF and EIGRP are more complex to configure, but you need to understand how distance vector protocols work in order to pass the CCNA!
About the Author:
Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of free CCNP and CCNA tutorials, The Ultimate CCNA Study Package, and Ultimate CCNP Study Packages.
For a FREE copy of his latest e-books, “How To Pass The CCNA” and “How To Pass The CCNP”, just visit the website! You can also get FREE CCNA and CCNP exam questions every day! Pass the CCNP exam with The Bryant Advantage!
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