issue with SLAAC and deprecated IPv6 addresses on recent windowsversions

[Scott Beuker]

Interesting bug, nice job in finding it.

I was talking to a friend who works at MS about what (if any) viable
avenues there are to report a bug like this and actually stand a chance
of getting it resolved. He recommend this:

http://connect.microsoft.com/WNDP/Feedback

I have no idea how much mileage you would get down this avenue, but if
you're feeling optimistic give it a shot, and let me know and I'll be
sure to create an account just to vote your bug up. :)

Thanks,
Scott



> -----Original Message-----
> From: ipv6-ops-bounces+scott.beuker=sjrb.ca at lists.cluenet.de
> [mailto:ipv6-ops-bounces+scott.beuker=sjrb.ca at lists.cluenet.de] On
> Behalf Of Christian Hahn
> Sent: Tuesday, December 01, 2009 8:54 AM
> To: IPv6 Ops list
> Subject: issue with SLAAC and deprecated IPv6 addresses on recent
> windowsversions
> 
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Hi list,
> 
> In a lab I did some testing with SLAAC and different OSs and recently
> stumbled
> upon an issue on recent windows versions. It is only present on Vista
> and 7, not
> on XP. But let me tell you the story ...
> 
> I deprecated an formerly (by RA) announced IPv6 prefix (let's say
> 2001:db8:1:2::/64) by  sending some RAs with PreferredLifetime=0 and
> ValidLifetime=7200 and thereafter stopped sending RAs.
> All windows machines behaved correctly and deprecated the addresses
> derived from
> that prefix. Outgoing connections no longer used it as source address,
> but
> incoming packets (like icmpv6 echo request) where answered due to the
> valid
> "ValidLifetime" value. ;)
> 
> Then in the second step (after some minutes of testing) I tried to re-
> activate
> the _same_ prefix (2001:db8:1:2::/64) by sending periodic RAs with
> PreferredLifetime=86400 and ValidLifetime=43200. And here the weird
> things
> began. On Vista and 7 the values for the "Lifetimes" where updated to
> the new
> ones derived from the RA, but the prefix status didn't change. It
still
> was
> stuck in status "deprecated". Hence the still valid IPv6 addresses
from
> that
> prefix (2001:db8:1:2::/64) wasn't used as source addresses for new
> connections,
> only old connections used it and incoming packets where answered.
> 
> On XP it was different. The prefix came back to life, changed to
status
> "preferred" and the system again used it's 2001:db8:1:2::/64 IPv6
> addresses as
> source address for new connections.
> 
> To proof it I replicated the test, and restarted all machines
> beforehand. But
> the result didn't change, hence it seems it is "stable" behavior.
> 
> I assume it's not the proper behavior, but found no clue in RFC4862
> (SLAAC)
> where I was looking for allowed status changes or similar.
> Has anybody seen a similar behavior or made similar tests with
different
> results?
> 
> BTW. I used radvd 1.1 on Ubuntu 9.04 on the router side.
> 
> cheers,
> Christian
> - ------------------
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