IPv6 multihoming

Brian E Carpenter brian.e.carpenter at gmail.com
Fri Feb 4 20:31:56 CET 2011

On 2011-02-05 02:44, Daniel Roesen wrote:
> On Fri, Feb 04, 2011 at 02:31:08PM +0100, Roger Wiklund wrote:
>> What's your take on this?
> IPv6 PI /48 multihoming works almost perfectly and that will approach
> 100% soon when the last anti-PI zealots fix their filtering policies.
> Most have given up resistance. Most/all reports I've seen from people
> operating on /48 PI blocks see no issues - but there are still (very
> few) networks with overly strict filters.

It is still a really bad solution strategically, because we know
it doesn't scale. So don't get too comfortable - this will *not*
be the long term solution for highly scaleable (millions of
customers) multihoming.

> PA more-specific multihoming works much less good - was always a broken
> idea to begin with.

If you mean that punching holes in PA blocks is a bad idea, I agree,
but really only for the same reason - it doesn't scale to millions,
only to thousands. Once people accept /48s, PI or PA are just about
the same.

If you mean a user site running two different PA prefixes all the
time, so that no holes need to be punched, that works out of the box,
although people don't seem to believe it. It also scales.

[long essay on the history of this problem deleted]


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