draft-ietf-v6ops-3177bis-end-sites WGLC

[George Bonser]

One thing that concerns me is this:

" RFC3177 suggested that some multihoming approaches (e.g., GSE) might
   benefit from having a fixed /48 boundary. This no longer appears to
   be a consideration."

As long as those approaches keep any smaller assignments out of the
global routing table, then fine.  It is going to be hard enough for
dual-stacked operators getting full routes to deal with the explosion of
/48 routes from PI space that will happen when the current v4 multihomed
nets start announcing their /48 assignments.

A v6 route consumes 4x the resources on a router as a v4 route does. 
A network that is multihomed on v4 will likely also be multihomed on v6.
A network will likely be multihomed on both protocols at the same time
initially and for some period after they begin to announce their v6
assignment.

Given the above, when the mass migration begins, there will be no
reduction in the v4 table and an explosion of the v6 table.  Routers are
going to blow up once the combined table gets to about 500,000 v4 route
equivalent.  Granted, due to the larger assignments in v6, the migration
of individual network blocks will not be 1-to-1 in that an end site with
multiple non-contiguous v4 small assignments can operate with a larger
v6 aggregate but nevertheless the v4 table will not shrink and the v6
table will grow.

I am currently accepting down to a /48 from PI space but not accepting
nets that small from PA space.  It is going to be pretty hard for folks
to try to multihome using PA space.  Even if they convince their
upstream to punch a hole in their aggregate and announce a smaller net,
getting other people to accept that smaller net is going to be a
problem.

In summary, anything smaller than a /48 in PI space is likely to be
useless if it is announced globally as many will not accept it.



> -----Original Message-----
> From: ipv6-ops-bounces+gbonser=seven.com at lists.cluenet.de
[mailto:ipv6-
> ops-bounces+gbonser=seven.com at lists.cluenet.de] On Behalf Of Fred
Baker
> Sent: Sunday, October 24, 2010 11:01 AM
> To: IPv6 operators forum
> Subject: draft-ietf-v6ops-3177bis-end-sites WGLC
> 
> The IETF IPv6 Operations Working Group is initiating a two week
working
> group last call of
> 
> http://tools.ietf.org/html/draft-ietf-v6ops-3177bis-end-sites
>   "IPv6 Address Assignment to End Sites", Thomas Narten, Geoff Huston,
>   Rosalea Roberts
> 
> In essence, this is a change to the advice that the IETF gave the RIRs
> in RFC 3177. We had indicated at that time that we believed that
> allocating a /48 to each end site was important, for various reasons.
> We at this point believe that a better model allows the LIR to
allocate
> diffrent length prefixes to their customers in accordance with the
> network's needs.
> 
> If you find issues, such as disagreeing with a statement or finding
> additional issues that need to be addressed, please post your comments
> to v6ops at ietf.org.
> 
> We are looking specifically for comments on the importance of the
> document as well as its content. If you have read the document and
> believe it to be of operational utility, that is also an important
> comment to make.