Case Studies - VPN error 721 and 800

Case 1: When a user attempts to access the Windows VPN server that is behind a Linksys WRT54G, he receives VPN Error 800 or 721.

Troubleshooting: Upgrading the firmware fixes the problem. Note: you may need to re-set the router.

Case 2: When a user attempts to access the Windows VPN server that is behind a router, he receives VPN Error 800 or 721. Also, telnet test fails on port 1723.

Troubleshooting: The port forwarding on the router pointed to the old Windows VPN server. Modify the port forwarding to point to the current VPN server.

Case 3: The client has been using VPN on Linksys WRV54G for a while. Now, he decides to setup Windows RRAS as the VPN server. He opens the port 1723 pointing to the Server and he can establish the VPN in the LAN. However, he can’t access the VPN from the Internet and receives error 800.

Troubleshooting: He forgot to disable the Linksys VPN. In other words, he enable VPN server on the router and also forwards port 1723 to the server. Disabling the VPN on the router fixes the problem.

Case 4: The user can establish the VPN from the desktop at home but not from the laptop.

Troubleshooting: He loaded Microsoft OneCare software that blocks the GRE. Reconfigured the OneCare settings fixes the problem.

Troubleshooting: Make sure other no secure software blocks your access, for example, if you use Norton secure software, you may need to add the remote client's IP so that the client can access.

Case 6: The VPN server receives Event ID: 20169 - Description: Unable to contact a DHCP server. The Automatic Private IP Address 169.254.x.x will be assigned to dial-in clients. Clients may be unable to access resources on the network.

Troubleshooting: The server cannot contact your DHCP server to get a
pool of addresses to allocate to clients and to itself for the internal
interface. It is better to use Windows DHCP instead of router DHCP. If you are using Windows DHCP, you may setup static IP pool.

Case 7: the client setup VPN server on a multihomed computer. The VPN client can't access VPN with error 800.

Troubleshooting: The client was setup 2 NICs with 2 gateways. The default gateway is the LAN NIC. When the VPN client tries to access it, we see it from the router log. However, the server reject the connection because these is not route return. The resolution is remove the LAN gateway as default gateway and use only VPN as default gateway.

VPN Setup

The VPN server should have a static IP address and assign the arrange IP addresses to ... The VPN server must also be configured with DNS and WINS server ...
www.chicagotech.net/vpnsetup.htm

Name resolution on VPN

Connection issues on DC, ISA, DNS and WINS server as VPN server ... To assign the DNS and WINS to a VPN client for name resolution, you should configure VPN ...
www.chicagotech.net/nameresolutionpnvpn.htm

RRAS/VPN Q&A Collections

Access remote computer using hostname over VPN without WINS and lmhosts · Accessing the Internet is low while connecting to a VPN ...
www.chicagotech.net/Q&A/vpnq&a.htm

VPN slow issues

Symptom 5: The download is very slow on VPN client after establishing the VPN. Cause: The VPN Client may use the remote network gateway. ...
www.chicagotech.net/vpnslow.htm

VPN Issues

Can't connect to a VPN server on the outside of the PIX ... If using the same laptop in a different location, the VPN works. ...
www.chicagotech.net/vpn.htm

VPN troubleshooting tools

VPN Troubleshooting Tools. 1. PPTPclnt and PPTPsrv to test GRE and PPTP. 2. IPCONFIG to troubleshooting connection and name resolution issues ...
www.chicagotech.net/vpnissues/vpntools.htm

VPN error 800