This artical covers how to configure dynamic NAT (Network Address Translation) on CISCO Routers.

Steps to configure dynamic NAT using CLI.

1. Login to the device using SSH / TELNET
2. Go into the config mode.
   

   Router#configure terminal

3. Configure the router’s inside interface
   
   

   Router(config)#interface fa0/0

   Router(config-if)#ip nat inside

   Router(config-if)#exit

4. Configure the router’s outside interface
   
   

   Router(config)#interface eth0/0/0

   Router(config-if)#ip nat outside

   Router(config-if)#exit


5. Configure an ACL that has a list of the inside source addresses that will be translated.
   
   

   Router(config)#access-list 1 permit 192.168.0.0 0.0.0.255

   
   Configure the pool of global IP addresses
   
   

   Router(config)#ip nat pool POOL01 4.4.4.1 4.4.4.5 netmask 255.255.255.0

   NOTE: The pool configured above consists of 5 addresses: 4.4.4.1, 4.4.4.2, 4.4.4.3, 4.4.4.4, and 4.4.4.5.

6. Enable dynamic NAT
   
   

   Router(config)#ip nat inside source list 1 pool POOL01

   NOTE: The command above instructs the router to translate all addresses specified in the access list 1 to the pool of global addresses called POOL01.

7. Exit config mode

   Router(config)#exit

8. Copy the running configuration into startup configuration using following command
   
   

   Router#write memory

   Building configuration... [OK]