RE: v6 subnet size for DSL & leased line customers

["Azinger, Marla" <marla.azinger () frontiercorp com>]

I'm glad to see more people are starting to look at this issue.  If you are just now beginning to look into the IPv6 
Multihoming issue I would start with reading a few strings on IETF, NANOG and ARIN mail lists and the following 
document posted 2 years ago at: http://www.nro.org/documents/pdf/MultihomeIPv6procon.pdf

Decisions need to be made soon and all kinds of policy can effect that.  Their are dueling issues at hand on this 
matter and we need to find a balance.  Traffic Engineering and Multihoming is an Engineering requirement.  Not 
exploding the tables is also a requirement.  Right now policy only inadvertently supports PI to be used for Multihoming 
and policy inadvertently does not support TE or Multihoming.  Not permitting TE or Multihoming on large networks is not 
going to be accepted by the large networks as an answer.  So it would be a "good thing" if our community could work out 
a balance that permits TE and Multihoming on a managed scale.  Otherwise those networks will just start doing whatever 
they want or need.

Cheers!
Marla

-----Original Message-----
From: owner-nanog () merit edu [mailto:owner-nanog () merit edu] On Behalf Of Vinny Abello
Sent: Wednesday, January 02, 2008 10:53 AM
To: Donald Stahl
Cc: Joe Abley; Iljitsch van Beijnum; Christopher Morrow; NANOG list
Subject: Re: v6 subnet size for DSL & leased line customers


Donald Stahl wrote:
> > in real life; people still find it necessary to carve up their
> > aggregates and announce more-specifics in strategic directions. I
> > would suggest that not *all* observed instances of such deaggregation
> > are due to operator ignorance
> There's a big difference between deaggregating a couple of bits for TE
> purposes and announcing 64 /24's from your /18 :)
>
> We need to decide what's acceptable as a community and then enforce it
> as a community. If someone starts announcing dozens of prefixes in v6
> then they get blocked they either get blocked or they get a filter
> that restricts them to their covering route (or blocks them if they
> don't have it).

On this note: In the v6 world when multihoming, what size network block is the minimum recommended allocation? In the 
v4 Internet, most major networks I've seen do not accept anything longer than /24 and this is what is allocated to 
customers with their own AS when multihoming regardless of the usage of the /24. I'm just curious if this is currently 
outlined somewhere already as what was decided. Are we going to see /64's, /56's or /48's polluting the v6 routing 
table just as /24's are today on the v4 table? I understand most of that pollution is not because of multihoming, but 
rather TE or negligence/lack of clue. With the advent of 32 bit ASN's, this could possibly become a concern however... 
that and people trying to do TE with their v6 space as they did with v4. I agree with the above reply that this needs 
to be ironed out as a community and was curious how multihoming customer networks fit into this equation.

--

Vinny Abello
Network Engineer
vinny () tellurian com
(973)940-6100 (NOC)
PGP Key Fingerprint: 3BC5 9A48 FC78 03D3 82E0  E935 5325 FBCB 0100 977A

Tellurian Networks - The Ultimate Internet Connection http://www.tellurian.com (888)TELLURIAN

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