Forwarding GRE Protocol to another machine

I have been putting different settings into conf file.  The GRE protocol 
doesn't have a "port number". The GRE is also known as IP/47.  I have tried 
plugging that information in but no luck so far. Win 2K PPTP uses TCP port   
1723 and this GRE protocol.  I tried netstat but it did not show anything. I 
did see TCP port 1723 open.  It can reach the server but fails to 
authenticate with the server because of this GRE. Any other suggestions?

Thanks,

Kevin.

_________________________________________________________________
Share your photos without swamping your Inbox.  Get Hotmail Extra Storage 
today! http://join.msn.com/?PAGE=features/es