Hairpin nat for a test environment

[nikmiddleton]

Hi Guys,

Currently trying to setup a test system and am struggling to make it work

We have 2 asterisk servers behind the firewall. In order to simulate a production environment, we want them to communicate over the eternal ip's.

Tried port forwarding and 1:1 NAT but no traffic. Turned on pure nat, also no joy.

I suspect that this is a hairpin NAT problem in that we want the traffic to go out via the wan interface, then back in to the other server. (both have virtual external IP's)

Any pointers?

regards