Network Warrior

Names

One of the more useful features of the PIX OS is the ability to display IP addresses as names. To enable this feature, enter the names command in configuration mode:

PIX(config)#names

With the names feature enabled, you can configure any IP address to be associated with a name. This is similar in principle to a basic form of DNS, but the names are local to the PIX being configured. Say that 10.10.10.10 is the IP address of a server called FileServer. Using the name command, you can assign the name FileServer to the IP address within the PIX:

PIX(config)#name 10.10.10.10 FileServer

You can then configure an access list like the following:

PIX(config)#access-list 110 permit tcp any host 10.10.10.10 eq www

Tip

Access lists, including features specific to the PIX, are covered in detail in Chapter 23.

In the configuration, the IP address will be translated to the configured name:

PIX#sho run | include 110
access-list 110 permit tcp any host FileServer eq www

If you prefer to see the IP addresses, you can disable the names feature by negating the names command. The configuration will once again show the IP addresses:

PIX(config)#no names
PIX(config)# sho run | include 110
access-list 110 permit tcp any host 10.10.10.10 eq www

Tip

Even with names enabled, the output of the show interface command will always show the IP addresses.

If you need to see all the names configured on your PIX firewall, use the show names command:

PIX#sho names name 10.10.10.1 PIX-Outside name 10.10.10.10 FileServer name ...