nanog mailing list archives

Re: Yahoo and IPv6


From: Jeff Wheeler <jsw () inconcepts biz>
Date: Tue, 10 May 2011 00:57:04 -0400

On Mon, May 9, 2011 at 10:04 PM, Joel Maslak <jmaslak () antelope net> wrote:
On Mon, May 9, 2011 at 3:57 PM, Jeff Wheeler <jsw () inconcepts biz> wrote:
I do take issue with your suggestion that /64 LANs are in any way
smart in the datacenter.  They are not.  I have some slides on this
topic: http://inconcepts.biz/~jsw/IPv6_NDP_Exhaustion.pdf

There are ways of mitigating this (the easiest is to use ACLs or firewalls
to limit traffic into a subnet from untrusted sources so that only
legitimate traffic is allowed).

Your suggestion has two main disadvantages:
1) it doesn't work on some platforms, because input ACL won't stop ND
learn/solicit -- obviously this is bad
2) it requires you to configure a potentially large input ACL on every
single interface on the box, and adjust that ACL whenever you
provision more IPv6 addresses for end-hosts -- kinda like not having a
control-plane filter, only worse

-- 
Jeff S Wheeler <jsw () inconcepts biz>
Sr Network Operator  /  Innovative Network Concepts


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