Hi Jeff,
Please see inline... Original From: JeffTantsura <jefftant.i...@gmail.com> To: 肖敏10093570; Cc: Abhinav Srivastava <absri...@gmail.com>;alexander.vainsht...@rbbn.com <alexander.vainsht...@rbbn.com>;rtg-bfd@ietf.org <rtg-bfd@ietf.org>; Date: 2023年03月27日 00:28 Subject: Re: [EXTERNAL] Can a BFD session change its source port to facilitate auto recovery Hi Xiao, please see inline On Mar 24, 2023, at 5:43 PM, <xiao.m...@zte.com.cn> <xiao.m...@zte.com.cn> wrote: Jeff, Please see inline... [jeff] the number of p2p connections between 2 directly attached IP end-points is rarely larger than 32 (either LAG or ECMP), SH BFD sessions are distributed across the path traversed and coherency between IP connectivity matrix and BFD sessions between any given pair of directly connected IP end-points can easily be guaranteed, end2end (MH BFD) is between non directly attached end-points and is subject to network topology and routing, and has to be re-evaluated on any change. INT doesn’t really help here, hashing decisions are local, any changes (local or global) might change the hashing results, unless you build a full mesh of source routed paths… but then, why BFD at all, you could use INT only instead, take a look at HPCC draft [XM]>>> I think it depends. I know that in some networks the hashing algo is common on all network nodes, so the hashing results are predictable. [jeff] how did we get to SR here? If you have got a strict source routed path, you only need to validate that path, if it is loose however, same issues [XM]>>> Jump thinking, sorry about that. :) Just to argue that MH BFD can be used beyond reachability. Best Regards, Xiao Min From: JeffTantsura <jefftant.i...@gmail.com> To: 肖敏10093570; Cc: absri...@gmail.com <absri...@gmail.com>;alexander.vainsht...@rbbn.com <alexander.vainsht...@rbbn.com>;rtg-bfd@ietf.org <rtg-bfd@ietf.org>; Date: 2023年03月24日 16:48 Subject: Re: [EXTERNAL] Re: Can a BFD session change its source port to facilitate auto recovery That’s not going to fly, number of ECMP paths in today’s networks could be anywhere between 2 and 500+, how many of these would you exercise, how would you know that you have covered all of them? [XM]>>> The number of links/LAGs seems much higher than the number of ECMP paths. If otherwise I have to run SH BFD on each link/LAG, why not try to run MH BFD on each ECMP path? :-) As to the coverage, BFD+IOAM may help, because IOAM can tell you the path BFD packet really takes.
