BGP Dampening

Sat Nov 16 01:16:20 UTC 2002

Greetings,
I pose this question do its puzzling major.  Two nights ago at
approximately 10:20 PM PST I started receiving enough invalid routes
that it caused my processor on router B to reach 100 percent utilization
for 30 second interval every 3 min. While doing a debug on updates I
discovered that router A was injecting routes from two of my transit
connections into my tables and then removing them. When I checked router
A there was  a dampening list being created, but still Router A passed
these routes on to Router B, but stranger still not on to Router C. When
I check router B there were no dampened paths in the tables.

My question is why didn't Router B dampen the invalid routes, and two
why did Router A pass them along to Router B, and not Router C?

Background
Router C: 7513, dual processor, full memory
IOS; Version 12.1(5c)E12, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1)

Router B: 7507, dual processor, full memory
IOS; Version 12.1(2)E, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1)

Router A: 12012, dual processor, full memory
IOS; GS Software (GSR-P-M), Version 12.0(21)ST2, EARLY DEPLOYMENT
RELEASE SOFTWARE (fc1)

Route Sources: there are 4 full tables coming into Router A, 3 of equal
preference and one of lesser preference. Yet the router still chose the
flapping route???? 

If this is not worthy of the groups time could someone please contact me
off list

Mark V. A. Bown
mark.bown at optigate.net
Optigate Networks Inc.
www.optigate.net