VPN connection problems

[gronow]

I set up a VPN to connect to my office LAN from home.
VPN server is NT4 with a public IP.
195.26.*.*
Private IP address pool set up for the VPN connections.
192.168.1.*
Clients are XP pro.
When trying to connect from home...
If my laptop is disconnected from my home LAN, I can connect to the office LAN over the VPN with a dial up connection.
As soon as the laptop is plugged into my home LAN, the VPN connection fails over the same dial up.
I want to connect over ADSL, so need to be on my home LAN.
I have a desktop on my home LAN which I can successfully connect to the office VPN, both with a dial up or ADSL through a router.
I have the VPN client settings the same on both machines.
The only differences I can think of are:
The laptop is part of the office domain but the desktop is not.
The Laptop has various alternate IPs set up:
192.168.1.* (for office LAN)
192.168.7.* (for home LAN)
195.26.*.* (public)

The desktop has one IP:
192.168.7.*

The VPN setup is obviously OK as it works on one machine and even works on the laptop if it is not on the home LAN, but there is something on my laptop preventing the connection when on my home LAN.
Both laptop and desktop can connect and browse the internet no problem through either dial up or ADSL.
Any ideas?

 

[John Lewis]

What are you seeing when the connection fails? Error messages and numbers, please.

 

[gronow]

Error 800: Unable to establish the VPN connection.

 

[gronow]

I cannot ping the VPN server from my laptop but can browse internet OK.
Any ideas?

 

[erikms]

Have you checked 'use default gateway on remote network' in the networking tab, advanced TCP/IP settings?
That might interfere with your home lan settings
-Erik

 

[nsvoy]

make some tests and tell me the results

make the dial up connection with an unplugged lan cable and after the establishment of the vpn plug the cable.

dial up no ip configured on NIC
dial up with only 192.168.7.* on nic
dial up with only 192.168.1.* on nic


The problem must be in the 192.168.1.* ip that you have configure on the laptop NIC.