[Openswan Users] What needs to be done to route data across ipsec interface?

[Eduan Basson]

Hi List

I need your help with trying to debug my connection between Linux and 
Windows.

I can establish an ipsec connection between my linux 2.4 running 
openswan and a Windows 2003 server, but I can't send any data across the 
ipsec0/NPF_GenericDiailupAdapter interfaces. I think this must be 
iptables or routing related.

What is the best practice for routing? Currently I set up a static route 
to the IPSEC/VPN server via my unencrypted interface (eth0 or ppp0, 
depending on whether I dial-up or not), and then I start openswan. After 
successfully completing quick mode 2, openswan automatically replaces 
this route with a static route to the IPSEC/VPN server via the encrypted 
interface (ipsec0). But my problem is, now I can't send any data to that 
server, because nothing will flow over ipsec0. If I manually remove this 
route and add one over the unencrypted interface, I can ping my server, 
but I can't netcat to port 1701 (for l2tp VPN) - no idea why. Shouldn't 
this be possible? And likewise, shouldn't it be possible across the 
encrypted interface as well?

All my iptables policies are set to ACCEPT, until I can figure out how 
to fix this issue. Is this enough to make sure that iptables isn't 
responsible for this blockage?

Any help will be greatly appreciated.

Eduan Basson