I have a windows 7 pro workstation with one network adapter that I have configured to accept incoming VPN connections. I can connect to it via VPN on the local subnet and it shows 1 incoming connection. However I can't connect to it from another machine over the Internet and I get error 800. I have a public IP that is NAT to the adapter and the only firewall in between is the Windows Firewall with Advanced Security. I've created 2 rules, 1 to allow TCP 1723 and another to allow GRE but it still won't accept connections. What could the problem be? I can connect to the computer via RDP so it doesn't appear to be a TCP firewall issue and I can also telnet 1723 from another computer on the Internet. Also, I have a SBS 2003 server that accepts VPN connections on another public IP address (in the same block) and that works fine. I've tried disabling the Firewall service altogether in Windows 7 Pro, but that seems to block all incoming connections.

Check this blog http://blogs.technet.com/b/rrasblog/archive/2009/08/12/troubleshooting-common-vpn-related-errors.aspx Vote As Helpful - if you find helpful :-)

This doesn't help. As I said in the original post, it's something specific to this computer accepting connections. The IP address and hardware firewall are ruled out because it works fine with SBS 2003 on the same hardware and IP. I've since been able to disable Windows 7 firewall and now connections are accepted. The problem is that permanently disabling the Windows firewall is unacceptable. I've tried adjusting the GRE settings in Windows Firewall with Advanced Security but to no avail.

This doesn't help. As I said in the original post, it's something specific to this computer accepting connections. The IP address and hardware firewall are ruled out because it works fine with SBS 2003 on the same hardware and IP. I've since been able to disable Windows 7 firewall and now connections are accepted. The problem is that permanently disabling the Windows firewall is unacceptable. I've tried adjusting the GRE settings in Windows Firewall with Advanced Security but to no avail.

Hi, Error 800: Unable to establish the VPN connection. The VPN server may be un-reachable, or security parameters may not be configured properly for this connection. You should doulbe check your firewall settings, pay attention to the profile step when you create the rule.(check all the options: domain, public and private) Another suggestion is to reset firewall to default, then add the rules for a test. VPN and Remote Access Connections Fail http://technet.microsoft.com/en-us/library/cc776171(WS.10).aspx Windows 7 - Virtual Private Network (VPN) - Enable Incoming VPN Connections http://www.sevenforums.com/tutorials/4517-virtual-private-network-vpn-enable-incoming-vpn-connections.htmlIvan-Liu TechNet Community Support

Hi, Error 800: Unable to establish the VPN connection. The VPN server may be un-reachable, or security parameters may not be configured properly for this connection. You should doulbe check your firewall settings, pay attention to the profile step when you create the rule.(check all the options: domain, public and private) Another suggestion is to reset firewall to default, then add the rules for a test. VPN and Remote Access Connections Fail http://technet.microsoft.com/en-us/library/cc776171(WS.10).aspx Windows 7 - Virtual Private Network (VPN) - Enable Incoming VPN Connections http://www.sevenforums.com/tutorials/4517-virtual-private-network-vpn-enable-incoming-vpn-connections.htmlIvan-Liu TechNet Community Support

This manual was helpful for me for error 800: http://www.vpnserverwindows7.net/vpn-error-800. Plenty of information about error 800 and vpn connectivity issues is here as well: http://social.technet.microsoft.com/Forums/en/w7itpronetworking/thread/b4b984b8-360a-4f9b-bd78-f0a2fe4fb347