I'm trying to figure out how to use VPN to add one small network (less than 10 machines) to another (also less than 10). Both Networks are in different states, with different ISPs. Basically, I would like to use a VPN pipe to make all the machines local from a network perspective. Ideally, I would like them to still route out their respective ISP pipes for internet queries.
Here is the topography as it stands now:
LAN A is routed by a CentOS 4.3 machine which acts as the OpenVPN server.
eth0 connects to the internet.
br0 is a bridge to all of the local LAN interfaces:
- eth1 - local wired ethernet connections
- wlan0 - local slow wireless connections (801.11b)
- ath0 - local fast wireless connections (802.11A)
- tap0 - virtual VPN interface
LAN B is routed by a Westell modem. I would like to replace this with a linux box, but am unable to at this time. However, there is a Sparcstation 4 on LAN B running Aurora 2.0b2 which has OpenVPN installed and is able to connect to LAN A.
Currently the Sparc machine can see all the machines on LAN A. Machines on LAN A are able to talk to the Sparc. However no other machines on LAN B can communicate with LAN A and nothing on LAN A can talk past the Sparc.
It seems to me that lots of corporations these days are connecting satellite offices to their LANs using VPN. So this should be possible, but I am at a loss to figure it out.
What I have tried:
1) Bridging the physical eth0 adapter on the Sparc with it's virtual (tap0) adapter. This broke VPN completely.
2) Building a static route table so that machines would see the sparc station as the route for connection to the IP space on the VPN. This didn't break VPN, but would not get traffic past the tap0 interface on the spark.
Is there a Howto out there to help me do this that I am missing? Everything I can find seems to be a client connection to a LAN. I can't find an example of a Network connecting to another Network via VPN. Thoughts, ideas, and suggestions are appreciated. Also, I only have until the 1st to get it working. After that, I have to go back to Real Life (TM).