I did an analysis of the DFZ with Emile Aben at RIPE. There may be a
million now, but at least half of these are TE and functionally
irrelevant to 90%+ of the rest of the BGP speakers, being aimed at
immediate peers only.
If we renumbered, the count of real announcements becomes very much
smaller, close to the count of ASN, modulo some necessary
Geoff has done work on this too, the ratio between noisy speakers and
the stable speakers appear to be constants modulo natural growth.
(Geoff says hello btw)
On Tue, Jun 28, 2022 at 7:41 AM Noel Chiappa <jnc(a)mercury.lcs.mit.edu> wrote:
From: Paul Ruizendaal
Will read those RFC's, though -- thank you
for pointing them out.
Oh, I wouldn't bother - unless you are really into routing (i.e. path
RFC-1992 in particular; it's got my name on it, but it was mostly written by
Martha and Isidro, and I'm not entirely happy with it. E.g. CSC mode and CSS
mode (roughly, strict source route and loose source route); I wasn't really
sold on them, but I was too tired to argue about it. Nimrod was complicated
enough without adding extra bells and whistles - and indeed, LSR and SSR are
basically unused to this day in the Internet (at least, at the internet
layer; MPLS does provide the ability to specify paths, which I gather is used
to some degree). I guess it's an OK overview of the architecture, though.
RFC-1753 is not the best overview, but it has interesting bits. E.g. 2.2
Packet Format Fields, Option 2: "The packet contains a stack of flow-ids,
with the current one on the top." If this reminds you of MPLS, it should!
(One can think of MPLS as Nimrod's packet-carrying subsystem, in some ways.)
I guess I should mention that Nimrod covers more stuff - a lot more - than
just path selection. That's because I felt that the architecture embodied in
IPv4 was missing lots of things which one would need to do the internet layer
'right' in a global-scale Internet (e.g. variable length 'addresses'
which we were forced to invent the term 'locator' because many nitwits in the
IETF couldn't wrap their minds around 'addresses' which weren't in
packet header). And separation of location and identity; and the introduction
of traffic aggregates as first-class objects at the internet layer. Etc, etc,
Nimrod's main focus was really on i) providing a path-selection system which
allowed things like letting users have more input to selecting the path their
traffic took (just as when one gets into a car, one gets to pick the path
one's going to use), and ii) controlling the overhead of the routing.
Of course, on the latter point, in the real world, people just threw
resources (memory, computing power, bandwidth) at the problem. I'm kind of
blown away< that there are almost 1 million routes in the DFZ these days.