1511 update, lose IPv6 connectivity a few minutes after reboot

I've installed the 1511 update (threshold 2) on my desktop computer. It has always worked correctly with my dual stack IPv4 and IPv6 LAN, with both Windows 8 and Windows 10. Now, after the update, it will initially have IPv6 working after I reboot. Then, after a few minutes, IPv6 will stop working, and I see "no internet connectivity" for IPv6 from the Network and Sharing connection properties, even though the other clients in my house still have IPv6 connectivity.

So far, I've tried using netsh to reset the winsock catalog and the tcp stack, and have installed the latest network interface driver from the OEM. I also tried disabling IPv4, and seeing if the network troubleshooter could get the IPv6 connectivity going. That didn't help, either.

At this point, this behavior is a mystery to me. Right now, no IPv6 on this desktop. If I rebooted the computer, IPv6 connectivity would be restored for a few minutes...I have no idea how to troubleshoot this one, it's just strange.

Any help or ideas on what directions to go with this?

Thanks!

Did you ever resolve this? My IPv6 is intermittently dropping, I just restart the connection and it goes again. But it keeps happening, very frustrating.

Did you ever resolve this? My IPv6 is intermittently dropping, I just restart the connection and it goes again. But it keeps happening, very frustrating.

Yes, but I don't recall what, if anything, that I did, specifically. That was a while ago. Not even sure if this turned out to be a router or Windows 10 problem at this point. However, sometimes, when I reboot my desktop, IPv6 will appear to be working, and then appear to go away. This is always a router problem, where IPv6 isn't really working on the router even though my desktop initially says so. I generally fix it by one of these methods, depending on the firmware:

1. Reboot the router.

2. Disable IPv6, reboot the router, and then re-enable IPv6.

3. If all else fails, reset the router to factory defaults, and manually re-enter my router settings.

4. In rare cases, a cable modem reset has been necessary.

You can also cross-check with tablets and phones, to verify that IPv6 is still available from your router when it drops on your desktop. Just use the "IPv6 test" web sites online on the Safari and/or Chrome browser, depending on whether you're Android or iOS.

Wish I remembered, but IPv6 always ends up working now, assuming that the router firmware allows it. I should keep a diary, mostly I just solve problems as they come up. Not keeping track of what I've done has me re-solving the same problem when it comes up again, which is also frustrating for me *smile*.

OK thanks, I understand. I actually removed Bitdefender, as the problem seemed to be since I installed that. Also, the other computer on the network wasn't showing any problem. Now things are fine again.... so must be Bitdefender...

OK thanks, I understand. I actually removed Bitdefender, as the problem seemed to be since I installed that. Also, the other computer on the network wasn't showing any problem. Now things are fine again.... so must be Bitdefender...

Could well be Bitdefender. I use Windows Defender. The thing that I initially didn't like about it, that it wasn't updated very often, was fixed by adding a virus definition update task using the task scheduler. The task that I added updates Windows Defender's virus definitions when I log on in the morning, and every hour it checks for a new virus definition update. Also, do manual Malwarebytes and Windows Defender scans once a week. Seems to be working well, although Bitdefender is highly rated.

You might try taking some time if you ever get it *smile*, to see what feature of Bitdefender is causing IPv6 to drop. Maybe just adding an exclusion or turning off some overly aggressive feature would do the trick?