Tag Archives: VPN

Disabling IPv6 in Vista

As part of troubleshooting the Cisco VPN with my Vista system, I’ve been asked to “turn off” IPv6, just in case. I decided to take the comprehensive approach, as described in the IPv6 for Microsoft Windows FAQ, and use the registry:

Add the following registry value (DWORD type) set to 0xFFFFFFFF:


This method disables IPv6 on all your LAN interfaces, connections, and tunnel interfaces but does not disable the IPv6 loopback interface. You must restart the computer for this registry value to take effect.

Beware that there are Windows features, most prominently in my experience Windows Meeting Space, which require IPv6 to function. I think IPv6 is pretty cool, though, so I’ll turn it back on and keep thinking about how to integrate it into our infrastructure.



It turns out that disabling IPv6 system-wide or just on the adapters involved in the VPN connection (Wireless and VPNVirtual adapters, in my case) has resolved the connectivity issues I have experienced most recently with the Cisco VPN. As someone who uses the IPv6-dependent applications, I find this less than optimal.

More IPv6 resources (added as I find them…)

VPN trouble in Waterman Café

I connected to Cat’s PAWS in the Waterman Café, and then ran the VPN client. I logged in and got connected. I received a GMail notification of an incoming message, and then started my mail client. Outlook couldn’t connect to imap.uvm.edu. I tried Thunderbird, which couldn’t connect either. Then I realized that none of my network apps were working.

I grabbed a screenshot of the VPN Status window, showing that I was connected. While I was saving that, I received notification from the VPN that my connection had been terminated. Grabbed a screenshot of that, too. Back to my office.

Forwarded the screenshots and the description above to Network Services. Maybe the logs will shed some light…