I have my network setup with a sonicwall device as the default gateway so all my traffic goes in and out through it. Now I have just setup a VPN on a cisco router from our local network of 192.168.5.X to another network of 172.16.1.X. The Cisco router with the VPN has 2 interfaces, one facing our lan switch and one facing the Internet going around the default gateway which is our sonicwall. The LAN side of the router has IP 192.168.5.15 and the default gateway has ip 192.168.5.254.
If I change the default gateway in my computer to 192.168.5.15 I am able to ping the computers on the other side of the VPN and everythign works fine, but if I leave the settings intact with my original default gateway which is 192.168.5.254 then I am not able to ping the devices on the other side of the VPN because all traffic is being sent to the sonicwall and my switches don't know that the 172.16.1.X network can be accessed if packets are sent to 192.168.5.15…
Long story short, how can I overcome this conundrum of having to change the gateway to access the VPN? How could I solve this problem? attached is a diagram to help you visualize the setup.
Best Answer
You just need to add in some extra routing.
In this case adding a static route on your sonic wall to route traffic to 172.16.1.0(/24?) via 192.168.5.15 as the next hop should take care of it.