openVPN tunnels

[R P Herrold]

On Thu, 2 Nov 2006, Nathan England wrote:

> When you create a tunnel from remote network A to remote 
> network B, does each side need to create a tunnel to the 
> other, or doesn network B just need to establish the tunnel 
> to network A ?

Only one end initiates the connection -- the other just 
receives it; then each can use a 'post' script to manage the 
needed change to the routing tables at each end; if the link 
times out, a post script after disconnect remotes that 
routing.

The link (tunnel) looks like a point to point link -- so long 
as the __routing__ at each end knows that the other subnet is 
at the remote end, and the endpoints sit at what is otherwise 
also the 'default router' gateway for that given subnet, it 
just works.

There was an issue of some NATing impedeing the link staying 
alive, (as I mentioned in this OLD post of mine, which touches 
on the routing needed), but that was cleared up long ago.  See 
the archived post at:
 	http://openvpn.net/archive/openvpn-users/2002-09/msg00013.html

> I have create a tunnel from network A to network B and from 
> network B to network A. Both are established. I can ping the 
> gateway from either remote network, but nothing beyond that.
>
> Does anyone know of any tutorials for setting up a vpn 
> between two networks?

almost certainly you have a routing mis-configuration issue in 
the post scripts

I have an extended writeup on this -- I'll try to find it an 
supplement this post.

- Russ Herrold