withdrawal propagation (was E.E. Times?)

Mon Jan 13 19:30:04 UTC 1997

> From: randy at psg.com (Randy Bush)
> > "William Allen Simpson" <wsimpson at greendragon.com>
> > An implementation that propagates _extra_ withdrawals shouldn't _hide_
> > behind "standards compliant".  In fact, I don't think _is_ either
> > "valid" or "standards compliant".  There is no standard that says "send
> > extra BGP withdrawals for routes that you are not currently announcing".
> > It was just a bug in the implementation.
>
> Nice to know you understand the cause well enough to assign blame.  Mind
> telling us all what it is?
>
Looking carefully at what I wrote, I do not see anything about "cause",
only the validity (and standards compliance) of an implementation that
displays this "effect".  Obviously, I made the assumption that these
effects were the results of an implementation, rather than a fabrication
or a figment of Craig's imagination.  Such a buggy implementation would
receive "blame", and a fix would be expected.

Perhaps there is some disagreement as to the existence of the
phenomenon?

Randy, do you disagree that there are routers:

 - sending more BGP withdrawals than announcements?

 - sending BGP withdrawals for routes that they have not announced?

 - passing along withdrawals from other routers' announcements seen on
   other interfaces, even though those routes are not announced by this
   router?

That was my understanding of the effect, and Craig's use of the word
"extra".  If I am in error, please publically correct my understanding
in detail, giving all the facts upon which you rely.

Also, please give a reference (section and paragraph) where these
phenomenon are specified as "valid" in one of our "standards".

Thank you.

WSimpson at UMich.edu
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BSimpson at MorningStar.com
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