Cisco IOS NAT on a Stick Configuration Example

[lagapidis (Lazarus Agapidis)]

Hello Maodo

@kayoutoure

Question-1

I do not see the signification of “PBR” in the lesson ?

If you notice after the second diagram, it states that any traceroute initiated from R1 to R2 will cause FastEthernet 0/0 to respond rather than going all the way to the loopback interface and back triggering a NAT translation. This is remedied by using PBR.

@kayoutoure

Question-2

In the first scenario, the answer is return back by a “Reply” arrow. But, in second and third scenarios, the answer is returned by a “NAT” arrow. What is the difference between “Reply” and “NAT” answers ?

The difference is that in the first case, no NAT translations take place. After PBR is implemented, NAT translations take place, packets reach the loopback interface and are returned back to R1 having already gone through a NAT translation.

I hope this has been helpful!

Laz