Re: [v6ops] Interesting problems with using IPv6

Nick Hilliard <> Tue, 09 September 2014 09:43 UTC

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Date: Tue, 09 Sep 2014 10:42:54 +0100
From: Nick Hilliard <>
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To: Mark ZZZ Smith <>, Brian E Carpenter <>, "Dale W. Carder" <>
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Subject: Re: [v6ops] Interesting problems with using IPv6
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On 09/09/2014 02:55, Mark ZZZ Smith wrote:
> I'd like to see them get to the bottom of and then fix these 'bridge
> loop' and other problems first before any value is placed on addressing
> their criticisms of IPv6. Other people have deployed IPv6 without these
> problems, so what is different between this network and everybody else's
> that doesn't have these sorts of problems?

from my reading of the post, the author+vendor determined that the bridge 
loops happened because the STP process was starved of resources on the 
switch CPUs.

This happened because the switch CPUs were overloaded with mld report 
packets due to end hosts on the extended L2 network replying to MLD 
all-groups queries every 150 seconds.

There were large numbers of MLD reports because there was a large number of 
ipv6 privacy addresses on the network.  The network operators did not have 
admin control of the end hosts and could therefore not stop them from using 
privacy addresses.