Hi. I received this clarification to the previous note and thought it would be best to send it out directly. Mark
From: Curtis Villamizar <curtis@ans.net> To: Jordan Becker <becker@ans.net> CC: Mark Knopper <mak@merit.edu>
Jordan,
I would like to propose the following changes to two of your paragraphs just to get the facts straight (since it is a large audience) without going into the gory details.
Curtis
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Also, there is a dormant bug in the RS6000 rcp_routed EGP code which involves routes getting imported via IBGP which do not get flushed out of a queue. When the regional router flaps (misses one message from the peer) due the 8KB+ update described above, the rcp_routed routes derived from EGP sitting in the queue do not get installed and this might indirectly result in a routing inconsistency between the ENSS and its CNSS neighbor.
Also, there is a dormant bug in the RS6000 rcp_routed EGP code which involves routes getting transferred internally via IBGP. If the regional router is able to maintain the EGP session but does not send it's own updates in a timely fashion due the 8KB+ update described above, the rcp_routed IBGP unreachable messages derived from EGP are queued but not flushed and do not get installed. This can result in a routing inconsistency between the ENSS and its CNSS neighbor and can lead to a period of CPU starvation under heavy packet load. Under some circumstances this can further aggrevate the routing flap.
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However this fix not solve the problem of the 8KB+ updates causing route flapping on several regional peer routers. Peer networks that are running BGP should not experience this problem. We have contacted Cisco, Proteon, and Wellfleet, and have learned the following regarding their suggested software fixes to this problem.
The change made to the T3 routing daemon addresses a secondary effect. However this fix does not solve the problem of the 8KB+ updates causing failure to reassemble large updates and possible route flapping on several regional peer routers. Peer networks that are running BGP should not experience this problem. We have contacted Cisco, Proteon, and Wellfleet, and have learned the following regarding their suggested software fixes to this problem.