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Refurbished Firewalls, Network Firewalls

Network Liquidators is your premier online destination for buying and selling refurbished firewalls. We keep an extensive inventory of refurbished firewalls in stock at most times which are usually available for overnight delivery. Along with our firewalls, we also carry many other networking products including memory, gbics, interface cards, network modules, switches, cables, and chassis.

All of our refurbished firewalls go through a grueling inspection, testing, and refurbishing process and all of our firewalls comes standard with our Lifetime Warranty (end-user customers only). For details about our inspection, testing, and refurbishing process, click here.

If you cannot find the used firewalls you are looking for, please call one of our account executives at 1-800-998-9862 for a custom quote. If you are not sure which firewall you need, we have technicians on staff experienced with networking products that can help you with your configurations.

We both buy and sell new, used and refurbished network firewall hardware and other networking accessories. Let us know if you have any surplus of refurbished firewalls that you are looking to sell and we will immediately reply with fair market value. Please call our purchasing department at 1-800-998-9862 ext 318. Below is a listing of some of our more popular firewalls. If you are looking to buy refurbished firewalls at a great price, then Network Liquidators is for you.

Refurbished Cisco Firewalls
Refurbished Cisco PIX Firewalls
Refurbished Cisco Firewall Base Units
Refurbished Firewall Interface Cards
Refurbished Firewall Parts & Components
Refurbished Firewall Memory
Refurbished Firewall Cables
All Refurbished Cisco PIX Firewall Equipment

Refurbished Cisco Firewall Memory

Refurbished Cisco PIX-515-MEM-32 Firewall Memory


Refurbished Cisco PIX-515-MEM-128 Firewall Memory

What are Firewalls?

A firewall is a system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently Refurbished to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.

Firewall Techniques:

Packet filter:
Looks at each packet entering or leaving the network and accepts or rejects it based on user-defined rules. Packet filtering is fairly effective and transparent to users, but it is difficult to configure. In addition, it is susceptible to IP spoofing.

Application gateway:
Applies security mechanisms to specific applications, such as FTP and Telnet servers. This is very effective, but can impose a performance degradation.

Circuit-level gateway:
Applies security mechanisms when a TCP or UDP connection is established. Once the connection has been made, packets can flow between the hosts without further checking.

Proxy server: Intercepts all messages entering and leaving the network. The proxy server effectively hides the true network addresses.
Refurbished Cisco Firewalls
refurbished firewalls
Refurbished Cisco PIX-515 Firewall
Refurbished Cisco PIX-515-R-BUN Firewall
Refurbished Cisco PIX-515E Firewall


Refurbished Cisco PIX-520 Firewall
Refurbished Cisco PIX-520-FO-BUN Firewall

Refurbished Cisco Firewall Interface Cards


Refurbished Cisco PIX-4FE-66 Interface Card


Refurbished Cisco PIX-1GE-66 Interface Card