Large global enterprises, multi-homing, and inconsistent announcements

[Craig A. Huegen]

Familiar indeed.

Cisco has applied for, and received, a /35 using the bootstrap criteria,
for the purposes of its internal deployment.

We would like to be able to break the /35 up into smaller-size chunks;
probably 16 maximum.  We would like to be able to announce each of the
resulting /39's from our Internet access points around the globe.  This is
just a first shot at it, so don't immediately shoot me; if you have a
better suggestion for us, let me know. =)

What we fear is that providers will perform route-filtering such that only
prefixes shorter than or equal to /35's will be heard, rendering our
address distribution and announcements inoperable.  In essence, the ENTIRE
/35 at that point will only support one location for Cisco -- most likely
San Jose.

/cah

On Wed, 18 Apr 2001, Brian E Carpenter wrote:

> Craig,
>
> You are right on that until the IETF multi6 group reaches some conclusions
> on short and long term IPv6 multihoming, we can't get final answers
> in this space. But meanwhile, my hypothetical large company is going to want
> to protect itself by getting a nice short provider-independent prefix.
>
> Doesn't this sound horribly familiar?
>
>    Brian
>
> "Craig A. Huegen" wrote:
> >
> > On Wed, 18 Apr 2001, Richard Jimmerson wrote:
> >
> > > It is ARIN's understanding that the community prefers ARIN not become
> > > involved in establishing global routing guidelines.  Does this continue to
> > > be true with IPv6?
> >
> > The reason I bring this up is because regardless of whether it's desirable
> > or not, service providers today are basing their v4 routing filters upon
> > allocation size.  Address space in 64/8 is much more flexible from the
> > perspective of an end user's ability to divide the block into regional
> > chunks, compared with 128/2 space.  Cisco ran into this in the past year
> > where, in an attempt to efficiently use the space granted to us over the
> > years, we wanted to announce portions of 163.213.0.0/16 as 4 sub-blocks,
> > each from one of our access points within the Asia-Pacific theatre.  This
> > would have resulted in a handful of providers not accepting the
> > announcements.
> >
> > We had two choices:
> >
> > * we could contact those providers we knew that filtered, and ask them to
> >   make exceptions for us.  Some of them refused, citing their legal
> >   departments would not let them make the necessary exceptions.  The other
> >   issue with this approach is that it's impossible to find out, except
> >   through a reactive approach, which providers are filtering and then make
> >   the necessary contacts to allow the blocks through; or,
> > * we could renumber into another block.  We did this, taking on
> >   significant expense to renumber into a like-size block that wasn't as
> >   tightly filtered.
> >
> > I believe that through the adoption of the IAB/IESG recommendations, ARIN
> > is affirming some of the concepts that pertain to routing.  Whether or not
> > it's believed that ARIN should be involved in establishing them, it's
> > happening as the guidelines exist today.
> >
> > Perhaps this could wait until the whole debacle surrounding multihoming
> > settles; I recognize that it may drive some of the decisions made
> > regarding these large enterprise networks.  Until some of those decisions
> > are made, any planning that's done by these enterprises (and therefore,
> > later: adoption) is going to be a dartboard throw.  It's harder to justify
> > within many of these enterprises.
> >
> > /cah
> >
> > ---
> > Craig A. Huegen  CCIE #2100                       C i s c o  S y s t e m s
> > Sr Network Architect, GCTS                              ||        ||
> > Cisco Systems, Inc., 400 East Tasman Drive              ||        ||
> > San Jose, CA  95134, (408) 526-8104                    ||||      ||||
> > email: chuegen at cisco.com                           ..:||||||:..:||||||:..
>

---
Craig A. Huegen  CCIE #2100                       C i s c o  S y s t e m s
Sr Network Architect, GCTS                              ||        ||
Cisco Systems, Inc., 400 East Tasman Drive              ||        ||
San Jose, CA  95134, (408) 526-8104                    ||||      ||||
email: chuegen at cisco.com                           ..:||||||:..:||||||:..