WIndows Updates Fail Via IPv6

Mikael Abrahamsson swmike at
Mon Nov 12 18:34:42 UTC 2018

On Mon, 12 Nov 2018, Mark Tinka wrote:

> I do run 6-in-4 from my backbone to my house as my FTTH provider does
> not do IPv6.
> I can't imagine this to specifically be the issue, as all other IPv6
> traffic is fine, but at this point, I'm open to suggestion.

Are you doing TCP MSS adjust/clamping? If you don't, try that and see if 
it helps. This might be a PMTUD issue.

Otherwise if possible, try lowering the MTU sent in RA to the one you have 
on your tunnel (this depends on if this is available to you in your RA 
sending device).

Mikael Abrahamsson    email: swmike at

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