local directive with DHCP

ksteuber

If I set my VPN client to start up automatically with the laptop, it connects to the VPN even when it is already on the same internal network as the VPN. This causes the computer to get a duplicate route to the LAN, making things malfunction.

All the solutions to this that I have seen say to use the "local" directive to specify which IP to listen on. This solution will not quite work for me because the IP I want it to listen on (the external IP) is assigned by my ISP using DHCP. I use dynamic dns to connect to the VPN, so the IP does not have to be static.

How can I set it up to only allow external connections? Should I use iptables to block that port on the internal network? I would rather not block things on my internal network if I can avoid it; I would prefer openvpn just always listen exclusively on the external interface.

ksteuber

Huh. It seems like it's working now. It still connects on the local network, but it drops all the packets because (according to the log) it is expecting them from the remote IP but is receiving them from the local IP. This configuration seems acceptable.

I don't really understand though. I think the only thing I changed was the protocol. I changed it from TCP to UDP after reading this link in the Forum Rules.

I don't get why it works, but as long as it works I guess it doesn't matter.