cannot connect to VPN

[nz7fvj]

Hi.
I have an issue where a friend is unable to connect to VPN on his new WIN XP computer .He has a cable modem and router at home . Without the router he is able to connect to VPN . With the router connected he gets error 800.He has an old Win 2000 computer with which he is able to connect to vpn even with the router connected.
He is using the default windows XP VPN client.
kindly let me know what the issue could be here..
thanks in advance..

 

[ChicagoTechNet]

with the router, can he ping the VPN ip? or use telnet to test it.

Robert Lin, MS-MVP, MCSE & CNE
Windows, Network, Internet, VPN, Routing and How to at

http://www.ms-mvps.com

 

[nz7fvj]

hi..
with the router connected he is able to get to the internet. He is not able to ping the VPN gateway cos that has ping restrictions.. thats the same even if he does not have the router connected. Basically when he is connected with the router .. he is getting error 800..

 

[zeuseason]

I wonder if you need to set the router to allow access for the remote computer. You may have to open a specific port if your router has a firewall. Contact your router's manufacture and maybe they can help. I think a typical open port in a router for VPN is 1723.

 

[gacollier]

NZ,

I'm wondering if the XP machine is using different port's to connect on the client end than the 2000 machine. Is a firewall in place on the router? If so, can you disable it? Here are the ports that you'll need for a PPTP VPN to work:

Client: 1024-65535/TCP
Server: 1723/TCP (PPTP)
Both ways: 47/IP (GRE)

Also, what happens when you telnet to the VPN server using port 1723? (ex: telnet xxx.xxx.xxx.xxx 1723). You should get a blank screen with a blinking cursor, not a connection error.

 

[chuka]

Remember that a router is a NAT device, you need to enable UDP encapsulation.