[nsp] Really strange NAT Problem

Adam Debus adam-lists at reachone.com
Thu Feb 26 11:51:14 EST 2004

> I am guessing your s0/0 interface provides your WAN connectivity. Since
> have an IP address on your loopback interface, and you seem to want it
> way, why don't you unnumber your s0/0 interface onto your loopback
> interface, making your s0/0 interface 'ip nat outside', and then
> your NAT statement onto the loopback interface?

> What this accomplishes is that your router knows that s0/0 is your 'ip nat
> outside' interface, but it knows to use the IP address of the loopback
> interface as its source.

In this box there are 3 interfaces:
FastEthernet0/0 - This is a connection to our edge via a wireless modem.
Serial0/0 - This is a DS1 connection to our edge.
FastEthernet0/1 - This is the connection to the inside network.

FE0/0 and S0/0 are running BGP back to the same router in the edge for
failover. That's why I've set it up the way I have.


Adam Debus
Network Engineer, ReachONE Internet
adam at reachone.com

More information about the cisco-nsp mailing list