KB 111

Why can't a browse the web after I've set up a MS VPN connection?

Article:111
Created:2001-04-03 18:41:30
Categories:
  Windows 98
  Windows NT 4
  Windows 2000
  Security

Question or Symptom

I'd like to be able to browse the web while I have a VPN set up, but once the VPN adapter is open I can't get to any web sites, except the corporate one.

Resolution

What you'll need to do is open the VPN DUN connectoid, select properties, press the network tab, select the TCP/IP protocol.

Then select properties and press the Advanced button. You should see a General tab. In this tab there's an option that is probably selected, labeled

 "Use default gateway on remote host". 
 Uncheck this box.

Now you should be able to make a connection to the VPN and browse the Internet at the same time.

What's going on here

What happens when you use the MS VPN connectoid is that it adds a second interface to your machine. At this time it also adds a second default gateway, and changes the routing metric on your first gateway to 2. This means any traffic not destined for your local area network will be sent over the VPN interface. This is unlikely to be routed by your corporate VPN network.

What we've done with this fix is to tell the VPN adaptor not to add this bogus default route. It has already added a route to the corporate IP space through your VPN interface so not adding the default router won't break the corporate VPN connection.