Trying to create a (OPC UA) connection between the PLC and an OpenVPN server, who are connected to each other via a RUTX08 acting as the OpenVPN Client.
First question: Is this possible with this setup?
Second question: If yes, which firewall/IP-table changes should I do to make it work?
Via the CLI on the RUTX08 I can ping the OpenVPN server (192.168.10.1)
I can NOT ping the PLC or PC (I guess all traffic to 192.168.10.xxx is directed to the WAN)
It seems like your RUTX08 has a route to the 192.168.10.0/24 network via both, LAN and OpenVPN.
In server’s OpenVPN configurations, check if it has a 'push route 192.168.10.0 255.255.255.0’ option configured. If it does - remove it. If it does not, check OpenVPN config on the client (RUTX) to see if it has an option 'route 192.168.10.0 255.255.255.0’. If so, remove it.
These options basically tell RUTX to send all packets destined to 192.168.10.0/24 via OpenVPN. However, this is incorrect because the 192.168.10.0/24 is actually on RUTX LAN, and not a network on the OpenVPN server.
If you will want to reach RUTX’s LAN from OpenVPN server (for example, PLC), you will need to add a route from OpenVPN server to 192.168.10.0/24 network via RUTX. For this, take a look at this post here.