[ih] The story of BGP?

[Noel Chiappa]

    > From: Justine Sherry <justine at eecs.berkeley.edu>

    > why was it settled on as what we all switched to in 1994? Were there
    > alternatives in mind?
    > ...
    > Does anyone have ... interesting experiences to share?

L-rd, I should be a total font of useful information here, because I was in
the middle of all of it, but alas, this period is dim in my memory - very
dim, sigh.

I know there was an EGP++ that a number of us worked on for a while (I forget
who led the effort, it must have been someone at BBN, I think). I don't
recall anything at all about it, alas (although I probably have some old
drafts in a large stack of papers upstairs if anyone _really_ cares). I
assume it must have loosened the 'no-cycles' restriction on EGP2 (I _think_
that's what we called the version of EGP that was widely deployed, which had
some differences from the version that Eric Rosen first proposed - but don't
put much weight on that memory), but I don't recall anything about it.

I think what happened next was that I became wholly dissatisfied with both
the direction and pace of EGP++, and tried to get Proteon, which was then in
tight with a lot of the NSF regionals, to lead an effort to do something
better - I wanted to do something link-state based - the working name was FGP
(in the spirit of the languages, B, C and D...).

I tried to convince John Moy that he was capable of doing it, but he demurred
(which was ironic, because only very slightly later he did OSPF - a
link-state routing protocol). Dave Clark backed up that position to the
Proteon board, so I wasn't able to convince Proteon to do it.

At about that time, or shortly thereafter, IBM won the NSF backbone contract,
and they needed something better than EGP, and so Yakov wound up putting
together BGP.

    > How is the BGP we switched to in 1994 different from the BGP we used
    > today, and who drove those changes?

Well, there were three main 'phases' (and I don't recall the order of
the first two, but I'm sure the RFCs will tell).

The first was that Yakov did an 'improved' BGP for use with the ISO stack,
and at some point an upgrade to the IETF BGP basically took that up. The
second was that the decision to do CIDR (the chief recommendation of the ROAD
effort) meant we had to upgrade BGP to carry masks. (These may have been
folded into one upgrade? Don't recall... Destination-Vector protocols,
they're all fundamentally junk, I don't pay much attention to the details.)

Since then, the third 'phase' is that there has been a series of improvements
(I think mostly done by adding attributes), things like communities, etc. And
there are things like route-reflectors. But I don't know if any of them are
major protocol changes, though (although repeat comment about lack of
attention to DV protocols).

	Noel