Yes, it is possible. Take a look at this cisco article:
"MC" <email@example.com> wrote in message
>I am trying to do NAT overload both directions between two locations in my
> One location being inside and one being outside.
> I can do the overload on the ethernet interface going from inside to
> I seem to have to use a pool to go from outside to inside.
> When I set this up I wanted to hide everything behind a single IP address
> pool, but seems it only lets one client on the outside to use a single IP
> in the pool at a time and not do PAT.
> I thought I had this working in another location I used to work at but
> been a while and can not remember.
> Is this possible ? another way to do it ?
> Can I have two interfaces be inside and overload between them ?
> Any sugestions would be greatful.