First off please forgive the really crass way i had to depict this...
Seems my visio 2003 didn't want to work on vista, very odd..
Here is a very bad hand-drawn pic of how the setup looks...
*The Mikrotik can ping R2 as it's on the same network
*Hosts on the internet can ping R2 but not 18.104.22.168
*Let's say for arguments sake i want to access the web interface Mikrotik provides on the 22.214.171.124 address
*The normall flow of traffic is from the PC's to the Mikrotik, to the server, which in turn NATS the traffic using 126.96.36.199 as the external IP.
*Both Server and Mikrotik Run OSPF however default routes are static
*Default route on Mikrotik is 192.168.1.1, so ALL traffic with unknown destination end up at the server.
Traffic comes in through R2 and is able to reach the Mikrotik router however because no other routes exist for hosts on the internet , it uses the default route sending traffic to the server for the replies breaking comms.
I have tested by specifiying a static route to my system at home to go to the R2 router and comms works fully.
Thus the need to use policy based routing to ONLY route traffic to R2 as the default gateway , IF the traffic originated from it in the first place.
Thank you for the example, i have tried messing about , but am still unable to get it right.
Don't know what im missing....