He's asking because if it was dark the interface would go down when the link was lost and the router would pull routes. But PA to FL would lead me to believe it'll be a wave from some type of DWDM gear which brings us to BFD. Luke Guillory Vice President – Technology and Innovation Tel: 985.536.1212 Fax: 985.536.0300 Email: lguillory@reservetele.com Reserve Telecommunications 100 RTC Dr Reserve, LA 70084 _________________________________________________________________________________________________ Disclaimer: The information transmitted, including attachments, is intended only for the person(s) or entity to which it is addressed and may contain confidential and/or privileged material which should not disseminate, distribute or be copied. Please notify Luke Guillory immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. Luke Guillory therefore does not accept liability for any errors or omissions in the contents of this message, which arise as a result of e-mail transmission. . -----Original Message----- From: NANOG [mailto:nanog-bounces@nanog.org] On Behalf Of Alex Lembesis Sent: Wednesday, March 21, 2018 11:31 AM To: Job Snijders (External); Youssef Bengelloun-Zahr Cc: NANOG Subject: RE: How are you configuring BFD timers? To speed up BGP routing convergence. The (2x) dark fiber links from PA to FL are being used as Layer3 datacenter interconnects, where each datacenter has its own AS. The DF is also carrying FCIP traffic, so we need failover to be as fast as possible. Best regards, Alex -----Original Message----- From: Job Snijders (External) [mailto:job@instituut.net] Sent: Wednesday, March 21, 2018 12:25 PM To: Youssef Bengelloun-Zahr Cc: Alex Lembesis; NANOG Subject: Re: How are you configuring BFD timers? Silly question perhaps, but why would you do BFD on dark fiber? Kind regards, Job 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.