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Forcing an issue is going to happen when the port goes down. The point is the ACL can make it more graceful for those directly affected and also those indirectly affected by the port going down by ensuring all BGP connections (MLPA and bilateral) are terminated with the directly affected members before the link goes down for the directly affected members. In this context: directly affected member = those whose path to the main fabric are going to be physically moved (includes downstream members on an extension switch that is being moved) indirectly affected member = everyone else who are not going to have their own path to the fabric go down I am not sure who would intentionally prefer a less graceful option of losing all/most MICE connectivity. The addition of very short lived ACL's on the exchange fabric ports for directly affected members does not preclude members from implementing their own proactive measures; people are certainly free to heed the announcement that they are going to be directly affected and pre-emptively shutdown all of their own BGP sessions at whatever time they want in advance and re-activate them anytime they choose afterwards be it minutes, hours or days later. The addition of the exchange enacted ACLs will help minimize the impact to the indirectly affected members who have bilateral peering with directly affected members. ________________________________________ From: MICE Discuss [[log in to unmask]] on behalf of Mike Horwath [[log in to unmask]] Sent: Wednesday, April 26, 2017 6:03 PM To: [log in to unmask] Subject: Re: [MICE-DISCUSS] Arista Round 3 Moves On Wed, Apr 26, 2017 at 09:34:21AM -0500, Andrew Hoyos wrote: > I???d disagree. The maintenance currently taking place affects more > than just the route servers. Plenty of people are doing bi-lateral > peering on MICE, and that *IS* affected by maintenance events like > these. Right - but that's for the bilateral peers to work on. Forcing the issue by adding an ACL that they may not have asked for seems kind of .. intruding. > Adding an ACL to the port ensures graceful shutdown/end of traffic, > rather than an abrupt drop and hold timer fun. I???d much rather > that someone running the maintenance and in control of the ultimate > link up/down events be the one deciding when things are > starting/ending and re-enabling traffic gracefully. I don't know if everyone accepts that. I'm playing devils advocate only. > > Clean shutdown of bird is easier, quicker, and will for sure make the > > multilateral peering not be further affected by bouncing repeatedly. > > Yes, great for MLPA, but not for bilateral. Bilateral users are already adding to their complication by having many more peers than just going multilateral. > Why break everyone and cause a total route server outage, when > it???s not necessary at all? Yesterday???s maintenance only > affected a portion of members. ACL???s on member ports would be the > cleanest way to minimize outage duration for all members with the > least impact to the IX as a whole. That member would have still been affected and would not have helped reduce the noise. -- Mike Horwath, reachable via [log in to unmask]