Re: [Idr] community of the day - common header

[Nick Hilliard <[e-mail]>]

Jeffrey Haas wrote:
> I'm not particularly fond of the theater that has gone into this discussion
> - and good will has been burned by that theater.  But regardless of the
> proposal to implement 4:4, 4:4:4, N:4 ipv6:4 or whatever we invent next
> month, let's nip this bit of deployment madness.

Jeff,

most people who have chimed in on this conversation understand the
underlying issues here:

- is -large- useful enough to dedicate an entire path attribute to it?
- do we try to merge with wide or something equivalent?
- do we aim for perfection or good enough?

Balanced against this, IANA allocated their last 16-bit ASNs at the end
of July this year, which means that the RIR tanks are nearly dry.  The
operator community has desperately needed >= 32b:32b for several years,
but no-one has made progress fixing this problem, until a couple of
months ago.

Our situation now is:

- the operational people who have contributed to this conversation think
that large is going to work for their requirements, and is worth deploying.

- there is running code (xr, bird and exabgp) which implements the large
proposal, and commitments from a bunch of other stacks, including non
open-source vendors.

- when you add new community subtypes, the point of diminishing returns
associated with the extra functionality is reached very quickly indeed.

- the existing 6-octet path attribute is still sufficient to deal with
signaling stuff that it was designed to handle.

- there has been no substantial progress on wide in 6 years.

There is nothing wrong with planning a kitchen sink approach.  The wide
draft has been adopted by IDR and nothing is stopping people from
working on it.  But in the best-case situation, it is still many years
away from wide-scale deployment.

If we were having this conversation in 2008-2009, which was the first
time that lack of >= 32b:32b communities started causing serious
operational problems, I'd be a good deal more sanguine about things.
But that time is over: it's 7 years later, and the entire operational
community is now staring at a fast-approaching brick wall.

Nick