Routing / IPTables question
 

I'm having trouble trying to understand iptables and linux routes.

I've gotten as far as doing iptables port forwards and routing specific ips to another network.

Say I have LAN A (192.168.1.0/24), one of the clients in this LAN has openvpn connection to an external server (192.168.100.0/24). Say the external client is currently connected as 192.168.100.2, and the LAN A client who's connected to openvpn is 192.168.100.1

I want other clients in 192.168.1.0/24 to be able to connect to 192.168.100.2 by ip, how do I do this? I routed 192.168.1.0 to 192.168.100.1, but I'm not sure where to go from there. Traceroute of 192.168.100.2 from other clients in LAN A shows it does get routed to 192.168.100.1 but does not get a response. What should I be doing on 192.168.100.1?

I'm not sure I quite understand what you wish to accomplish.

Do you have a client, "X", on the 192.168.1.0/24 LAN connected to 192.168.100.0/24 via OpenVPN, and would like other clients on the 192.168.1.0/24 network to use X's OpenVPN tunnel to reach the 192.168.100.0/24 network?