Windows 7: VPN Gurus: error 721

hi,
i wanted to implement a vpn connection using microsoft technology.
i enabled ras on the host computer which has win 7. the host computer sits behind a di-524 router, so i've enabled pptp pass through and ipsec pass through, moreover, i set a port forwarding for 1723 and 500 (both tcp and udp) to the host computer.

from the guest computer, who sits in a different subnet and uses win xp, i used telnet to verify that the host server can be reached, there was no problem reaching it. then i verified the generic routing encapsulation (gre) is set too, so i've used pptpclnt and pptpserv, and gre check complete successfully.



still, when i set a vpn dialup connection, i get error 721 (after verifying username and password).

any vpn guru can help me here?
thanks.

I received error 721, which says the remote computer is not responding.

• Cause: This issue can occur if the network firewall does not permit GRE traffic (IP protocol 47). PPTP uses GRE for tunneled data.
• Solution: Configure the network firewall between the VPN client and the server to permit GRE. In addition, make sure that the network firewall permits TCP traffic on port 1723. Both of these conditions must be met to establish VPN connectivity by using PPTP. For more information, see article 888201, "You receive an "Error 721" error message when you try to establish a VPN connection through your Windows Server-based remote access server" in the Microsoft Knowledge Base.
• Troubleshooting remote access VPNs: Virtual Private Network (VPN)

This is what comes up for error 721. Hope it helps.

i am here since i did all of that already
but thanks anyway.

In that case I would double check your set up because everything points to the same type of problems with error 721.

You also need to set up your dial up connection and modem to answer automatically. Your ISP also need to support VPN's. You are also supposed to use static IP's for your home VPN machine and using a full time internet connection would be better.

These VPN's can be tricky to set up and if one little thing isn't right they don't seem to work too well. If there is an A/V software involved you might need to uninstall it completely.

Try adding TCP 47 to the port.

See my reply in your double-post.

http://www.sevenforums.com/network-s...92994-vpn.html