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Re: withdrawal propagation (was E.E. Times?)
From: "William Allen Simpson" <wsimpson () greendragon com>
Date: Mon, 13 Jan 97 19:30:04 GMT

From: randy () psg com (Randy Bush)
"William Allen Simpson" <wsimpson () 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 () UMich edu
    Key fingerprint =  17 40 5E 67 15 6F 31 26  DD 0D B9 9B 6A 15 2C 32
BSimpson () MorningStar com
    Key fingerprint =  2E 07 23 03 C5 62 70 D3  59 B1 4F 5E 1D C2 C1 A2
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