MMat
I have run into a simple problem, for which however I am unable to to find a solution online.
I have setup many OpenVPNs in the past, bridged, routed, site-to-site, but never on a gateway, which is my current problem. I have built my own router, Debian Wheezy, acting also as DNS and DHCP server. The LAN (192.68.73.0/24) is reached via eth0, the WAN via br0 which gets its IP dynamically from my ISP (192.168.1.128, btw).
When a client connects, it gets an IP through the server-bridge directive within my LAN range, but hey, there's the rub: routing and DHCP are so configured that the router tries to reach the OpenVPN client through the LAN interface, eth0, rather than back through the WAN interface, br0. I can clearly see, by means of tcpdump, upon pinging the router from the OpenVPN client, the ARP traffic on the LAN eth0 interface, rather than either tap0 or br0.
It is clear that the router should be instructed to route packets for the OpenVPN clients via the very same interface the original queries came from (an hairpin) rather than the LAN interface. How do I do this? I know this must be possible because dd-wrt does it, but since I do not have a dd-wrt available to copy the configuration file, I am asking local gurus for guidance.
Read the manual here and here is a perfectly acceptable answer, thank you.
MMat
I found the answer myself: I need to add a route back to the client through the bridge br0, not through the virtual interface tap0. Otherwise, it is just like setting up a normal OpenVPN.
