Weird problems with IPv6 under windows

[vitruss]

Hi all!

I need help with IPv6 under my windows PC. I have HE tunnel running on router with everything working from the router. I also have a server under Linux (Arch), connected by wire, which also works with no problems.

But my windows laptop (connected through WiFi) could ping only some IPv6 enabled hosts. For example it resolves ipv6.google.com and facebook.com, but can't ping both, but can resolve and ping vk.com. The laptop pings my server and HE tunnel endpoint without any problems.

I've tried everything, but nothing helps. Are there any ideas where the issue is?

[cholzhauer]

Have you checked your mtu?

[vitruss]

I've tried to alter MTU on windows with netsh down to 1200. I've noticed some packages going back, but still 50% lost.