Configuring Dynamic NAT: One Private to One Public Address Translation

Note:

For a complete configuration of NAT/PAT with a diagram for visual assistance, see the sample configuration at the end of this chapter.

Step 1: Define a static route on the remote router stating where public addresses should be routed.	ISP(config)#ip route 64.64.64.64 255.255.255.255.128 s0/0	Informs the ISP router where to send packets with addresses destined for 64.64.64.64 255.255.255.255.128
Step 2: Define a pool of usable public IP addresses on your router that will perform NAT.		Private address will receive first available public address in pool
	Corp(config)#ip nat pool scott 64.64.64.70 64.64.64.126 netmask 255.255.255.128	Defines the following: Name of pool is scott (The name of the pool can be anything.) Start of pool is 64.64.64.70 End of pool is 64.64.64.126 Subnet mask is 255.255.255.128
Step 3: Create an ACL that will identify which private IP addresses will be translated.	Corp(config)#access-list 1 permit 172.16.10.0 0.0.0.255
Step 4: Link the access control list (ACL) to the pool of addresses. (Create the translation.)	Corp(config)#ip nat inside source list 1 pool scott	Defines the following: The source of the private addresses is from ACL 1 The pool of available public addresses is named scott
Step 5: Define which interfaces are inside (contain the private addresses).	Router(config)#int fa 0/0
	Router(config-if)#ip nat inside	You can have more than one inside interface on a router. Addresses from each inside interface are then allowed to be translated into a public address
Step 6: Define the outside interface (the interface leading to the public network).	Router(config)#int s 0/0
	Router(config-if)#ip nat outside