[LARTC] VPN through PPP

[Steve Comfort]

Hi all,

This is probably not the right place for this question, but maybe 
someone can help me out. I am trying to setup a VPN between two private 
addresses, using iproute2 (which is my only excuse for mailing this list).

The setup is as below :
           
           eth0                               ppp0                     
Wireless              ppp0                     eth0

     192.168.200.202           192.168.94.134          <----->       
 192.168.94.132             192.168.2.200


Both eth0 (strictly ixp1) and ppp0's are on wireless boards that we make.

I have basically followed the VPN Howto and done the following :

  ip tunnel add net0 mode gre remote 192.168.2.200 local 192.168.200.202 
ttl 255 dev ppp0
  ip link set net0 up
  ip addr add 192.168.200.202 dev net0
  ip route add 192.168.2.0/24 dev net0

I have tried various combinations of the above, using the ppp IP address 
for remote and the eth0 for local, etc, etc. (4 possible combinations).

I do the reverse on the other end of the tunnel, but do not see any 
traffic over this lot. I am able to ping and ssh between the two 
wireless boxes.

I do have a firewall, configured to do NAT on the PPP interface. I have 
also tried excluding the destination addresses from being NAt'd but this 
didn't make any difference.

Any suggestions would be greatly appreciated.

Best regards
Steve Comfort