Richard A Steenbergen wrote on 16/03/2011 19:03:
On Wed, Mar 16, 2011 at 06:56:28PM +0200, Tassos Chatzithomaoglou wrote:
Are there any transit providers out there that accept using the BFD (or any other similar) mechanism for eBGP peerings? If no, how do you solve the issue with the physical interface state when LANPHY connections are used? Anyone messing with the BGP timers? If yes, what about multiple LAN connections with a single BGP peering?
Well first off LAN PHY has a perfectly useful link state. That's pretty much the ONLY thing it has in the way of native OAM, but it does have that, and that's normally good enough to bring down your EBGP session quickly. Personally I find the risk of false positives when speaking to other people's random bad BGP implementations to be too great if you go much below 30 sec hold timers (and sadly, even 30 secs is too low for some people). We (nLayer) are still waiting for our first customer to request BFD, we'd be happy to offer it (with reasonable timer values of course). :)
Link state is good for the local connection. If there are multiple intermediate optical points (not managed by either party), or a lan switch (IX environment), you won't get any link notification for everything not connected locally to your interface, unless there is a mechanism to signal that to you. -- Tassos