Hi Yuya, Thanks. Your explanation looks reasonable because section 8.2: " If no other PE had advertised an Ethernet A-D route for the same segment, then the PE that received the withdrawal simply invalidates the MAC entries for that segment." Does not say "MUST" or "SHOULD". But the word "may" in this sentence was better to use. OK. I understood. It is an optional feature that was not claimed optional plainly. Eduard -----Original Message----- From: BESS [mailto:bess-boun...@ietf.org] On Behalf Of Yuya KAWAKAMI Sent: Wednesday, December 8, 2021 3:58 AM To: Vasilenko Eduard <vasilenko.eduard=40huawei....@dmarc.ietf.org>; bess@ietf.org Subject: Re: [bess] Contradiction for the RFC 7432 definition of the fast convergence (withdrawal) for single-homed CEs
Hi Eduard, As my understanding, these statements are not contradictory because mass withdrawal is an optional functionality. Section 8.3 says when PEs are operating All-Active redundancy mode, Ethernet A-D per Ethernet Segment Route must be advertised for split horizon. This would be reason why section 8.2.1 says "not needed" in case of single-homed scenarios. I understand these sentences as: - Implementations can use Ethernet A-D per ES routes to achieve mass withdrawal for single-homed CE (optional) - If Implementations want to achieve mass withdrawal, Ethernet A-D per ES routes should be used The implementation I'm using does not support mass withdrawal for single-homed CE. If there is any misunderstanding, I would appreciate it if you could point it out. Thanks, Yuya On 2021/12/08 4:24, Vasilenko Eduard wrote: > Hi EVPN guru, > > It looks like RFC 7432 section 8.2.1 (Constructing Ethernet A-D per Ethernet > Segment Route) has an error: > "The Ethernet A-D route is not needed when the Segment Identifier is set to 0 > (e.g., single-homed scenarios)." > > Because without "per ES route" it would not be possible to signal > "mass withdrawal" If CE-PE connection would fail That plainly promised for > single-homed CEs in section 8.2: > " If no other PE had advertised an Ethernet A-D route for the same segment, > then the PE that received the withdrawal simply invalidates the MAC entries > for that segment." > Or implied in section 17.3: > "The Ethernet A-D per ES routes should be used by an implementation to > optimize the withdrawal of MAC/IP Advertisement routes." > > Have I missed something? > > Eduard > > _______________________________________________ > BESS mailing list > BESS@ietf.org > https://www.ietf.org/mailman/listinfo/bess > _______________________________________________ BESS mailing list BESS@ietf.org https://www.ietf.org/mailman/listinfo/bess _______________________________________________ BESS mailing list BESS@ietf.org https://www.ietf.org/mailman/listinfo/bess
