Can't get VPN to work

[Zucarita9000]

I've set up our Windows Server 2003 to accept incoming connections, enable VPN pass-through in the router and forwared ports 1723, 1701 and 500 to the server.

I created a VPN connection from my Win XP machine at home, and it succesfully creates the connection and finds the server, but I can't login. The process just stalls when checking the User Name and Password (I entered the correctly). Is there anything else I have to set up?

 

[RebateMonger]

Are you trying to make a PPTP or an L2TP VPN?
Is there an error message (error code) from the Microsoft VPN client when the login fails?

 

[Zucarita9000]

I tried with both, none of them worked. The error I get is "Error 721: Remote PPP peer or computer is not responding."

 

[Zucarita9000]

I forgot the say that the router is a Linksys WRT54G. I've been reading about it, it seems that Error 721 is a common issue.

 

[Zucarita9000]

Ok, I've configured Port Triggering on ports 500 and 1723 (read about in another forum). It's working now, I'm able to connect to the server. Now what do I do? How can I get access to the remote network?

 

[RebateMonger]

Error 721 occurs when you aren't forwarding Protocol 47 (GRE) through the router to the VPN server. It's a VERY common error with PPTP VPNs. The makers of low-end routers can't seem to consistently forward GRE. One version of their router will do VPN passthrough fine. The next version won't work.