Cisco IOS Cookbook, 2nd Edition

Translating in Both Directions Simultaneously

Problem

You want to translate both internal and external addresses.

Solution

In some cases, you might need to translate IP addresses on both sides of your router:

Router#configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)#access-list 15 deny 192.168.1.15
Router(config)#access-list 15 permit 192.168.0.0 0.0.255.255
Router(config)#access-list 16 deny 172.16.5.25
Router(config)#access-list 16 permit 172.16.0.0 0.0.255.255
Router(config)#ip nat pool NATPOOL 172.16.1.100 172.16.1.150 netmask 255.255.255.0
Router(config)#ip nat pool INBOUNDNAT 192.168.15.100 192.168.15.200 netmask 255.255.255.0
Router(config)#ip nat inside source list 15 pool NATPOOL overload
Router(config)#ip nat inside source list 16 pool INBOUNDNAT overload
Router(config)#ip nat inside source static 192.168.1.15 172.16.1.10
Router(config)#ip nat outside source static 172.16.5.25 192.168.15.5
Router(config)#ip route 192.168.15.0 255.255.255.0 Ethernet0/0
Router(config)#interface FastEthernet 0/0
Router(config-if)#ip address 192.168.1.1 255.255.255.0
Router(config-if)#ip nat inside
Router(config-if)#exit
Router(config)#interface FastEthernet 0/1
Router(config-if)#ip address 192.168.2.1 255.255.255.0
Router(config-if)#ip nat inside
Router(config-if)#interface Ethernet0/0
Router(config-if)#ip address 172.16.1.2 255.255.255.0
Router(config-if)#ip nat outside
Router(config-if)#exit
Router(config)#end
Router#

Discussion

Sometimes you need to ...