Posted: Mon Apr 17, 2023 20:00 Post subject: connect server to client network
I have a working openvpn connection from an X86 client router running DD-WRT v3.0-r50176 to a Ubuntu 18.04 lts server running OpenVPN 2.4.4 x86_64-pc-linux-gnu. This works perfectly. I want to be able to connect from the server to devices behind the client router (ssh, http, etc). I can ping the client router, connect via ssh and via http using the tunnel ip address but not the ip address of the router (neither the WAN or the LAN address). When I ping the client router using the LAN/WAN address then by using tcpdump I can see pings enter the tunnel at the server end but using tcpdump at the client end I see no icmp ping messages. When I do the same with the tunnel address, there is a ping icmp message and reply visible with tcpdump at both ends.
Why do I see the icmp ping enter the openvpn tunnel at the server but not exit the tunnel at the client? What should I be checking to make this work?
That explained the required content of the CCD files and how to use iroute. It all works perfectly now. Hopefully the link will help anyone else looking at this thread.