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ios router multiple subnets assigned to one nat pool

I have a 2821 Router with two gigabitethernet interfaces. I am currently using PAT for inside to outside translations. The link is to an application vendor and we have been experience some diffuculities. They want me to stop using PAT and switch to dynamic nat. I have two class c subnets that we need to assign to a pool so that each internal client will dynamically map to one of the class c public ip's.

How can i have multiple subnets in one pool statement or is this even possible? I know with nat on the PIX it is, but with nat on a router I am unsure.

VIP Purple

Re: ios router multiple subnets assigned to one nat pool


indeed you cannot use multiple subnets in a single pool. You could try the following approach: define two pools and configure route maps. Let´s say your two internal subnets are and, and you want to translate those to and, respectively; the configuration would look like this:

ip nat pool POOL1 prefix-length 24

ip nat pool POOL2 prefix-length 24


ip nat inside source route-map MAP1 pool POOL1

ip nat inside source route-map MAP2 pool POOL2


access-list 101 permit ip any

access-list 102 permit ip any


route-map MAP1 permit 10

match ip address 101


route-map MAP2 permit 10

match ip address 102

Obviously the IP addresses used in this example are probably not yours, so change them accordingly...

Can you try and see if this works for you ?



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