Connecting to VPN net-to-net

Question

System administration

The question is next.
At the head office, there is a configured d-link dfl-800 router, on which VPN is raised via IPsec using a pre-shared key.
External address 192.168.10.1
Internal address 192.168.0.1

The branches have routers of the same family, but dfl-210. Accordingly, a tunnel will be built between offices. Everything works perfectly. The settings on the branch routers are simple.

Now there is a need to replace the router, in one of the branches, with a full-fledged server. We assembled the machine, filed down the routing, hung the squid, and that's all that was needed ... After that, it became necessary to raise the VPN client to connect the network-to-network type to the head office router. And rushed dancing with tambourines.

The server is debian 7. There are 2 network interfaces (external and internal). What tools to use to connect to the VPN gateway and organize a simple network "network - network".
I tried to use openswan, but I could not find a normal working config.

Answer 1

If ipsec is everywhere, then on debian it is most logical to raise the same protocol.
“normal working config” is different for everyone, so I would first look for demons that can build ipsec tunnels (openvpn?) and then read their manuals in depth

Answer 2

http://pfsense.org/ recommend to consider