Re: IPv6 /64 links (was Re: ipv6 book recommendations?)

[Karl Auer <kauer () biplane com au>]

On Wed, 2012-06-06 at 10:35 -0400,
Jean-Francois.TremblayING () videotron com wrote:
> The ND noise generated is arguably higher than ARP because of DAD, 
> but I don't remember seeing actual numbers on this (anybody?). 
> I've seen links with up to 15k devices where ARP represented 
> a significant part of the link usage, but most weren't (yet) IPv6. 

That doesn't sound right to me.

a) DAD only happens when an IPv6 node is starting up. ARP happens
whenever a node needs to talk to another node that it hasn't seen in
while.

b) DAD only goes to solicited node multicast addresses, i.e., only to
those nodes that share the same last 24 bits as the target address. ARP
goes to every node on the link (broadcast).

c) Similarly, ND (the direct equivalent of ARP) goes only to solicited
node multicast addresses, ARP goes to every node on the link.

So I'm not sure how DAD traffic would exceed ARP traffic.

Regards, K.

-- 
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Karl Auer (kauer () biplane com au)
http://www.biplane.com.au/kauer

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