Yesterday's Windows update causes IPv4 to be default

Mikael Abrahamsson swmike at
Wed Nov 14 18:18:45 CET 2012

On Wed, 14 Nov 2012, Dick Visser wrote:

> Anyone else has seen IPv6 issues on Windows since yesterday?

"An IPv6 readiness update is available for Windows 7 and for Windows 
Server 2008 R2".

It seems to address 6to4 mainly, but it has some "broken IPv6 
connectivity" as well.

Anyhow, after installing it on my 64bit Win7 Home Premium, I don't see any 
of your issues. As far as I can tell, it thinks my IPv6 works fine and 
uses it just like before.

I have a /48 tunneled to my home out of our regular PA IPv6 block, and I 
set IPv6 MTU to 1400 on my home lan (to avoid PMTUD RTT delays).

Mikael Abrahamsson    email: swmike at

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