Subject: RE: (ngtrans) Update to Provider Independent addressing format drafts

From: "Michel Py" <[email-masked]>
Date: Thu, 25 Oct 2001 17:58:02 -0700

I could not agree more with Tim. Add to the picture that Tim painted
connections with dozens of customers, providers or partners, all of them
having BGP peers, static routes and access-lists on their routers
referring to the block to be renumbered, and you make renumbering almost
impossible because you have to coordinate it with a score of third party
companies that might have other priorities than adapting their own setup
because one needs to renumber.

Michel.

-----Original Message-----
From: Tim Chown [mailto:[email-masked]] 
Sent: Thursday, October 25, 2001 3:49 PM
To: Keith Moore
Cc: [email-masked]
Subject: Re: (ngtrans) Update to Provider Independent addressing format
drafts

On Thu, 25 Oct 2001, Keith Moore wrote:

> > Renumbering a 100-router, 300-server, 24x7 $1M/day revenue
generating
> > room is quite another one.
> 
> I've been involved with renumbering of ~300 IPv4 machines of widely
varying
> platforms, in less than an hour, on multiple occasions.   It took
prior 
> planning, a bit of coding, and a mechanism for quickly finding the
machines 
> on which the renumbering failed.  But it wasn't rocket science.
> If we had standard tools to do this it would be even easier.  

Hi Keith,

Is that 300 servers, or mostly clients?  If you have a few hundred, or
thousands of domains with (virtual or otherwise) mail, web and other
(perhaps black box) services hosted then while I agree the renumbering
isn't rocket science, it's not much fun logistically.   There's domain
registrations to update, firewalls to change, a fair few Windows
applications which insist on IP numbers being keyed in manually, smooth
mail transitions, updates on other people's references to your IPs, 
and plenty of places where IPs are hard coded on Unix systems.  I agree 
prior planning is key, but to suggest most sites can press a button
and have it done in an hour seems optimistic :-)

At present operators such as Worldcom have smaller enterprises over a
barrel for bandwidth charges.  As bandwidth costs fall, and you see
rival
operators prices looking far more attractive, perhaps up to 50% less,
it's not a no brainer to move operator because you have to renumber,
and your current operator knows that, and can keep their fees higher for
you regardless.   If IPv6 were able to offer less painful renumbering
(which will need help from the likes of Checkpoint and Microsoft), or
we had some non-NAT form of provider-independent addressing, great.  But
as it is, smaller enterprises who don't have leverage to take address
blocks with them suffer when seeking competitive bandwidth rates.  With
NAT perceived as the "easy" form of provider independent addressing, I'm
not convinced we won't see IPv6 NAT.

tim

---

From: Iljitsch van Beijnum <[email-masked]>
Date: Fri, 26 Oct 2001 09:26:17 +0200 (CEST)

> because one needs to renumber.

I disagree. I have personally renumbered two relatively small ISPs
(including customers!) a total of three times. That would be 5 - 20
routers and 10 - 40 servers.

When compared to a lazy afternoon of doing nothing, renumbering is a lot
of work. When compared to the routine maintanance that happens anyway over
a period of several months, the added trouble of renumbering is fairly
negligible.

BTW: changing domains isn't much of a problem: just register a new address
for your name server.

Iljitsch van Beijnum

---

From: Brian E Carpenter <[email-masked]>
Date: Fri, 26 Oct 2001 14:20:38 +0200

Remember that v6 renumbering can include a period of overlap between the old
and new prefixes, when both will work and neither of them is deprecated. For
a large site with the kind of issues you describe, I would expect this overlap
to be quite long - at least a month, why not longer? This will greatly simplify 
the coordination problem. 

In fact, a single homed site changing to a new provider would become
multihomed during the overlap period; and an n-homed site would become
(n+1)-homed during the overlap period. A good multi6 solution *is* a
renumbering mechanism.

  Brian