[c-nsp] NAT and hairpin's

[Geyer, Nick]

Hi Everyone,

 

Just wondering if anyone has come up with a way to hairpin traffic using
a Cisco router? The problem is as follows;

 

Say for example I have a router connecting to the Internet and an
internal LAN doing normal NA, e.g;

 

203.1.2.3 -> ROUTER <- 192.168.1.0/24 (203.1.2.3 being the public IP on
the "outside" interface)

 

I have an application that talks from clients on the Internet to an
internal server (192.168.1.1), with the appropriate static NAT's setup
on the router to forward the traffic. The problem is the internal
clients also need to talk to the server but on the public IP address
(203.1.2.3). The traffic from the internal clients will hit the router
but it wont translate and forward the traffic because its coming from
the "inside" interface (and the static NAT only works for requests from
the outside interface).

 

I don't believe it can be done but just thought I would ask in case
anyone has come up with a weird and wonderful way.

 

Cheers,

 

Nick Geyer.