NAT ICMP, possible?

laichenkang · ‎04-23-2008

Hi all

I would like to NAT ICMP (ping) packets from source 10.250.1.105 to appear from source 172.29.186.180. I am using Cisco Router 2811. I can't seem to figure this out. Can any kind soul provide some sample config?

Thank you

Jon Marshall · ‎04-23-2008

ip nat inside source static 10.250.1.105 172.29.186.180

int fa0/0

ip nat inside

int fa0/1

ip nat outside

where fa0/0 is where the packet with the original src IP arrives and fa0/1 is where it goes out.

This will NAT all traffic for 10.250.1.105 to 172.29.186.180.

If you just want NAT ICMP only

access-list 101 permit icmp host 10.250.1.105 any

ip nat inside source list 101 10.250.1.105 172.29.186.180 route-map NAT

route-map NAT permit 10

match ip address 101

Jon

Jon Marshall · ‎04-23-2008

Posted twice by mistake.

thefindjack · ‎04-23-2008

Why would you need to use the route-map?

Jon Marshall · ‎04-23-2008

You don't necessarily need it but it does depend on how you want to do the NAT. So if you just want a static translation between 2 IP's

ip nat inside source static 1.1.1.1 2.2.2.2

If you want to qualify the NAT you can either

1) ip nat inside source list 101 interface fa0/1 overload#

ip nat inside source list 101 pool NATPOOL

or

2) you can use a route-map.

I just thought i'd use a route-map :-)

Jon