Came across a strange (ish) problem this week. I use a PPTP VPN connection from my Vista laptop to connect into our company network, but for the last few weeks I’ve had trouble getting the VPN to connect.
In the Vista “Connect to a network” dialog all configured VPN connections often show “This connection requires an active Internet connection” - with a big red X! No amount of refreshing or restarting would persuade it to enable the Connect option. And then randomly it would start to work …. All the while I had an internet connection which was working fine.
However, I also had the Microsoft Loopback Adapter installed to support some development testing I was doing. When I disabled the Loopback Adapter the VPN connections were immediately available to connect. Seems that the VPN is picking up my Loopback Network Adapter before the Wireless or Wired LAN adapter - not finding a route to the internet - and therefore failing.
So the solution/workaround is to disable the Loopback Adapter. I’m sure there’s a way to order the network adapters such that it tries the Wireless/Wired connections first - but it’s not much of a hassle to disable the LBA so I really can’t be bothered finding out!
I couldn’t find much on the web about this and only stumbled upon the solution in a rare flash of inspiration (!) so thought I’d write a quick blog which perhaps might help someone else ….



June 13, 2007 at 5:57 am
Thank you, Iain - your article did help me when my VPN connection suddenly stopped working in the same manner. And yours is the only helpful post about this issue that I could find - so thanks again ))
June 19, 2007 at 9:34 am
Sweet, I could have struggled for hours to get my VPN to work. You saved me a lot of time!
June 19, 2007 at 11:43 pm
I was having the same problem, and I found your blog entry in Google. In my case, I didn’t have a loopback adapter installed, but I do have VMware installed, which adds two virtual adapters for virtual machine networking. I disabled those, and that fixed the problem. So, thanks!
June 26, 2007 at 12:26 pm
I corrected this problem WITHOUT disable the loopback adapter. I just need to change the binding order of loopback adapter as the bottom at Network Connections, Advanced, Advanced Settings, (TAB) Adapters and Bindings settings.
June 26, 2007 at 2:00 pm
Hi all,
Well I’m chuffed that there is an answer I have the same issue after installing VMWare. My problem is now … where do I change the binding order in Vista ?
Cheers
June 26, 2007 at 2:00 pm
email is incorrect … should read dominicb41@hotmail.com
June 26, 2007 at 9:04 pm
Dom, as Felicio said in #4, open up the list of “Network Connections,” press the alt key, click Advanced, Advanced Settings, Adapters and Bindings tab. Searching windows help for “binding” should provide a more detailed walk through. YMMV, but worked for me. Thanks again to lain for posting this nugget of knowledge.
June 27, 2007 at 12:23 am
I agree with Felicio - changing the binding order of the adapters is much better as it resolves the problem rather than just working around it. Chances are if you have a loopback adapter or VMware adapter installed then you actually need it for something and disabling it isn’t ideal!
This does seem to be a fairly common issue so if I get time over the next day or two I’ll probably do up some screenshots in the blog with some step-by-step instructions.
June 27, 2007 at 1:10 pm
YAY … I have found it. It was the TAB key that I was un aware of that shows the menu!! Admins every where used to the “old” school may have an issue with this. And I know there will be many more little gotya’s in Vista from the admin business perspective.
Anyway, after finding the bings order I see that all is correct regards what comes first i.e. Local Area connection 1 , or 2 etc. Still is all good fun discovering Vista. I actually like it very much.
Thanks all your info and help. Iain keep the blog going I’m sure it’s going to be most useful.
Cheers
-dom
June 27, 2007 at 1:38 pm
And theres more.
I rushed the post a second ago thorough shear excitment! So please excuse the typos.
Iain I reckon a few screen shots showing the bits of vista would be truly wicked for everyone new to the issue.
Cheers Chaps
-dom
July 16, 2007 at 4:03 pm
Changing the binding order does not seem to working for me. I have vmware installed and am trying to access a multicast stream using VLC. The multicast packets are always getting routed to the vmware adapters (which obliviously will not work). My main adapter is set first in the binding order. I even moved things around and VLC always sends it multicast packets to the same vmware adapter. Any ideas? If i change the metric in route table is works fine. But I cannot expect my end users to be able to have that level of expertise.
September 11, 2007 at 9:10 am
Big thanks to Iain and Felicio. By moving my loopback adapter further down the bindings list, suddenly the “Connect To” dialog becomes *useful* again for hooking up a VPN!
November 7, 2007 at 12:28 am
I have experienced this the same problem using ODBC to configure my sql, with MS loop installed it seems to accept or block the Server broadcast on the network. if I disable loop back adapter I can see all the SQL servers on my network.
The other is our application tries to communicate with LEAD_SERVER DICOM Server, with Loopback adapter enable the DICOM server this the loopback adapter is requesting info instead of the built in lan with valid IP and DNS…
Has anybody got screen hot for Vista and XP…
December 16, 2007 at 12:38 am
very interesting, but I don’t agree with you
Idetrorce
December 20, 2007 at 1:03 pm
I would like to see a continuation of the topic
March 7, 2008 at 4:06 pm
I have XP with wireless card and a built-in Ethernet card on my laptop. Internet access was through either connection depending on where I am. After a loopback adapter was installed, the internet connection will not work unless I disable the loopback adapter.
Moving down the loopback adapter on the binding list didn’t help. But, when I changed the IP address on the loopback adapter to 10.10.10.10 (Non-routable IP), the internet connection is working again.
March 17, 2008 at 10:46 am
i just made a new virtual machine connection between c drive and e drive c drive is my main operating system and e drive is my back up hard drive i want to install windows xp on and i have now i need help connecting e drive to the internet can any one help me here please??
March 27, 2008 at 9:53 am
Tim, I’d like to help but don’t really follow the question at all. Can you give us a better description of what you want to achieve?
April 22, 2008 at 1:58 pm
Thank you Iain. I had same problem and the reason was same as Dave. Thanks Dave from Japan.