Vista - VPN Connection and Loopback adapter can't coexist

[Uric]

I have a software which installs a loopback adapter on the machine. I
noticed that if I have a VPN
connection on the machine (e.g. to connect to the Internet via ADSL),
the VPN connection sometimes
becomes unusable after adding the loopback adapter, and the "Connect
to a network" dialog states
"This connection requires an active Internet connection".
After a restart, the VPN connection is _always_ unusable with the same
error message.

After a bit of Googling, I found these two links:

http://www.crsw.com/mark/Lists/Posts/Post.aspx?ID=35
http://iainmagee.wordpress.com/2007...ack-adapter-requires-active-connection-error/

Both claim the problem is caused by the loopback adapter appearing
first in the binding order.
However, changing the binding order seems to require restarting the
machine, which I hope to avoid.
An alternative to rebooting (which I haven't fully tested yet) is
disabling and re-enabling all network
adapters on the machine. This is also something I prefer to avoid, as
this means the product cannot
be installed over the network or by terminal services.

Is there a way to get a VPN connection to work, while a loopback
adapter is present on the machine?
I would be happy to either get the binding order to take effect
without a reboot (or disabling/enabling
the adapters), or to cause the loopback to be bound last while
installing it.

Thanks in advance,

Yair Kuszpet

 

[Robert L. \(MS-MVP\)]

I think the problem is routing issue. Posting back with the result of
ipconfig /all when connecting to the VPN. Or this search result may help.

routing issues on vpnResolution: When establishing VPN to the office A, the
routing table changes. To fix this issue, disable the "Use default gateway
on remote network"" on the ...
www.chicagotech.net/routingissuesonvpn.htm


--
Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on
http://www.ChicagoTech.net
How to Setup Windows, Network, VPN & Remote Access on
http://www.HowToNetworking.com

 

[yairku]

Bob,

Thank you for your reply.

The problem is that I cannot even connect to the VPN, since the
"Connect to the network" dialog displays the error I mentioned below.
This reproduces even while connected to a regular office LAN, by
creating a VPN connection with a dummy IP address, and then adding a
new loopback adapter. After rebooting, the new VPN connection becomes
unusable, and cannot be connected.

I don't believe this is a routing issue, since in the scenario I
outlined above, there is full Internet access (e.g. pinging and
browsing). Only the VPN connection seems to think there is no
connectivity.

Yair