Have Cisco 37xx series router. On its DS3 wan interface it has a 99.x.x.x public IP address. On its lan interface it has a 172.x.x.x private IP address. The 172 address just routes between it and another linux based router. When doing traceroutes through the router when the source is on the lan side it responds using the 172 IP. I would like it to respond to all requests using the 99.x.x.x IP. How do I do that?
I accomplish this on the linux based router with preferred source but not sure on cisco.M