This article will help you through the steps to configure dynamic NAT on Cisco devices. You will be able to create the corresponding Configlet commands using Network Configuration Manager application. This will help you perform the same operation on multiple devices simultaneously.
With dynamic NAT, you specify two sets of addresses on your Cisco router:
Unlike with static NAT, where you had to manually define a static mapping between a private and a public address, with dynamic NAT the mapping of a local address to a global address happens dynamically. This means that the router dynamically picks an address from the global address pool that is not currently assigned. It can be any address from the pool of global addresses. The dynamic entry stays in the NAT translations table as long as the traffic is exchanged. The entry times out after a period of inactivity and the global IP address can be used for new translations.
If you don't have NCM installed, please click here to download and install the application.
Enter configuration commands, one per line. End with CNTL/Z.
Router(config-if)#ip nat inside
Router(config-if)#ip nat outside
Router(config)#access-list 1 permit 192.168.0.0 0.0.0.255
NOTE:The access list configured above matches all hosts from the 192.168.0.0/24 subnet.
Router(config)#ip nat pool MY_POOL 184.108.40.206 220.127.116.11 netmask 255.255.255.0
NOTE: The pool configured above consists of 5 addresses: 18.104.22.168, 22.214.171.124, 126.96.36.199, 188.8.131.52, and 184.108.40.206.
Router(config)#ip nat inside source list 1 pool MY_POOL
NOTE: The command above instructs the router to translate all addresses specified in the access list 1 to the pool of global addresses called MY_POOL.
Building configuration... [OK]
The corresponding configlet can be created in NCM application as shown in below screenshot.
Also you can click the below button to download the Configlet as XML and import it into NCM application using file import option.
|Configlet Name||Configure Dynamic NAT - Cisco|
|Description||This configlet is used to configure dynamic NAT on cisco devices|
|Execution Mode||Script Execution Mode|
ip nat inside
ip nat outside
access-list $ACL_ID permit $SOURCE_ADDRESS $SUBNET_MASK
ip nat pool $POOL_NAME $POOL_START_ADDRESS $POOL_END_ADDRESS netmask $NETMASK
ip nat inside source list $ACL_ID pool $POOL_NAME
show ip nat translations