Using 200 ms / 200 ms / x3 on either metro dark fiber or longhaul waves (Paris / Frankfurt / Amsterdam) successfully.
Best regards. Y. 2018-03-21 16:11 GMT+01:00 Alex Lembesis <alex.lembe...@tevapharm.com>: > Using 250ms x 3 on fiber connecting Pennsylvania to Florida... > > Best regards, > > > > Alex > > -----Original Message----- > From: NANOG [mailto:nanog-boun...@nanog.org] On Behalf Of Jason Lixfeld > (External) > Sent: Wednesday, March 21, 2018 9:10 AM > To: NANOG > Subject: How are you configuring BFD timers? > > Hey, > > For those running BFD on your land-based point-to-point links, I’m > interested in hearing about what factors you consider when deciding how to > configure your timers and multiplier. > > On paper, BFD between two devices over a local or metro dark fibre or wave > seems pretty trivial: Assuming your gear can a) support echo mode b) > hardware offloads echo processing c) automatically treats echos as vital > and puts them into the appropriate high priority queue, then setting the > timers down to their lowest possible values (3ms on some of the gear that > I’ve seen) and some low multiplier seems more than reasonable. But? > > From another angle, your link isn’t dark fibre or a wave but, for example, > ethernet over some sort of IP based L2 Transport, and is still a low (sub > 1ms) one-way latency local or metro link. How do you set your timers, and > what do you base that on? > > From yet another angle, what if your link is a long-haul wave, or for that > matter a wave of any distance that imposes a one-way latency that is higher > than the minimum tx and rx timers that are supported by your gear? We’ll > assume an unprotected wave, because I’m sure if it’s protected, you have no > choice but to consider the one-way latency of the longest of the two > segments. > > I made some assumptions above about support for echo mode and hardware > offload, but what if (some of) your gear doesn’t support some or all of > that stuff? How do you factor your configuration decisions? > > Thanks! > > This message is intended solely for the designated recipient(s). It may > contain confidential or proprietary information and may be subject to > attorney-client privilege or other confidentiality protections. If you are > not a designated recipient you may not review, copy or distribute this > message. If you receive this in error, please notify the sender by reply > e-mail and delete this message. Thank you. >
