VPN / Bridge

[Bob Kersten]

Hello,

I've been trying to create a tunnel/bridge between two networks which  
both reside behind a FreeBSD router using NAT. I've achieved it using  
the handbook example in chapter 14.10. Clients on network A are able  
to ping clients on network B and clients on network A are able to map  
samba shares on the NAT box/gateway of network B. The example however  
uses two different subnets to route traffic between both networks.  
Unfortunately broadcasts will not travel through the tunnel which  
causes Apple's bonjour (called rendezvous earlier) not being able to  
discover clients on the other network.

What I want to achieve is what I believe a bridge between both  
networks. The entire network A should be on the same subnet as  
network B:

network A
range 192.168.100.100 - 192.168.100.199 / 255.255.255.0
   |
FreeBSD gateway A
en1: IP: 192.168.100.101 / 255.255.255.0
en0: public IP: 25.25.25.1
   |
Internet
   |
FreeBSD gateway B
en0: public IP: 25.25.25.2
en1: IP: 192.168.100.1 / 255.255.255.0
   |
Network B
range 192.168.100.1 - 192.168.100.99 / 255.255.255.0

Using the example from the handbook there was no additional  
configuration necessary on the clients on both networks, the FreeBSD  
gateways handled all the necessary routing. It would be great if this  
new setup should also not require any additional settings on the  
clients aswell.

Can anyone give me an example or the necessary steps to create this  
kind of VPN?

Cheers,
  Bob.