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Re: [v6ops] Interesting problems with using IPv6

Fernando Gont <fernando@gont.com.ar> Tue, 09 September 2014 14:29 UTC

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Date: Tue, 09 Sep 2014 11:16:47 -0300
From: Fernando Gont <fernando@gont.com.ar>
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To: Brian E Carpenter <brian.e.carpenter@gmail.com>
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Cc: IPv6 Operations <v6ops@ietf.org>, l.wood@surrey.ac.uk
Subject: Re: [v6ops] Interesting problems with using IPv6
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On 09/09/2014 04:20 AM, Brian E Carpenter wrote:
>>> OK, but I would also like to understand why we require
>>> MLD messages for a Solicited-Node multicast address to
>>> set Router Alert.
>>
>> Because in theory the multicast router needs to process the MLD message
>> to build its forwarding table....
> 
> Why, for the Solicited-Node group, which is only meaningful on the link
> from which the MLD message arrives?

Then, let me change the question: Why do I need MLD for *this*?

We probably use MLD because "If you use multicast, you use MLD". Truth
is that, *unless your switch does MLD snooping* (and hence you *need*
MLD, or else your packets will not flow around), you could completely
kill MLD, and ND would still work just fine.

Not to mention that there are nodes that default t running MLDv2 *for
this* (way overkill, IMO)

Thanks,
-- 
Fernando Gont
e-mail: fernando@gont.com.ar || fgont@si6networks.com
PGP Fingerprint: 7809 84F5 322E 45C7 F1C9 3945 96EE A9EF D076 FFF1

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