I have a vendor that is on a 192.168.100.0 network and we are on a 10.0.0.0 network. I have deployed a router on their site so they can pass traffic to us and traffic back to them. We don't have a 172.18.xxx.xxx network that they have behind the 192.168.100 0 network that they have but we need to pass the traffic back to them.
They need to access servers on our side but they can not reach them, I can ping their network but from their 192 network they can reach our network but not from the 172 network. Do I need to add routes in our core or distribution side so that the traffic is returened? We also use EIGRP but they do not. we have a very complex network any assistance would be appreciated.