CCNP-CIT NAT configuration. pls clear my doubt.

Hi,

I am preparing for my CCNP-CIT exam and i had a doubt regarding one of the simulations that has been found in the exam nowadays.

actually there is a simulation on NAT which has the following specificatios...

-----r1--------------r2----------------r3---- s0 s1 s0 s1 s0 s1

r1= lan router(private ip address) r2= gateway router r3= internet router( public ip address)

NAT is configuted on r2 so that users on lan(r1) should be able to access the internet router(r3) with a public ip address.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++ The following configuration is done on r2

ip nat inside source list 1 interface loopback 0 overload

#access list 1 permits all lan ip address#

on interface s0 of r2 ip nat inside on interface s1 of r2 ip nat outside

there is a loopback address(public ip address)configured on r2 which is not used for any other purposes.

=============================================================== MY confusion is ...

Whether an "ip nat outside" is required on loopback 0 interface

If any one can help, it would be really appreciated.

thanks in advance dabance.