I have a question that is more network related than FreePBX related.
One of our clients has a router that is provided and managed by the “mothership”. They have no access to it and the cannot ask for any modifications (very tedious everytime). However, the company policy allows them to have a second router with a second internet connection. They want to use this second connection for VPN access and to connect outside IP phones (the FreeePBX is local)
I’m pretty sure I can setup something for them, but I have a question regarding the “gateway”.
Let’s say I have a second Internet connection with a fixed IP, configured in the second router. This router has a LAN interface connected in the LAN network. I know that all traffic originating from the devices on the LAN will go to their default gateway, which is the “locked down” main router. BUT, if I have traffic incoming in the second Internet connection, through the second router (like a VPN connection or a SIP phone registration, through port forwarding), once this traffic reaches it’s destination on the LAN, will the “replying” traffic go back the way it came to the second router or will it be directed to the default gateway (main router), thus breaking everything ? I’m pretty sure that the traffic will go back the same way it came in, but I need to be sure and I cannot really test it for now.
Note: Adding a route to the main router to redirect some traffic to the second router is not possible.