Hi Folks, We are receiving a lot of moderation requests for this topic due to the long list of recipients. Please keep only BESS list as a recipient for any further message so the message will be published automatically on the list.
Thanks in advance, From: BESS [mailto:bess-boun...@ietf.org] On Behalf Of Andrew G. Malis Sent: Tuesday, October 09, 2018 16:54 To: jwbens...@gmail.com Cc: Muthu Arul Mozhi Perumal; Alexander Vainshtein; shell.nak...@ecitele.com; yechiel.rosengar...@ecitele.com; michael.gorokhov...@ecitele.com; dmitry.vald...@ecitele.com; ron.sday...@ecitele.com; bess@ietf.org; Rotem Cohen Subject: Re: [bess] Signaling Control Word in EVPN James, Agreed. We touched on that in section 7 of draft-ietf-pals-ethernet-cw, where we advised operators that enabling post-CW DPI for ECMP calculations could cause misordering. Cheers, Andy On Tue, Oct 9, 2018 at 10:35 AM James Bensley <jwbens...@gmail.com<mailto:jwbens...@gmail.com>> wrote: On Tue, 9 Oct 2018 at 15:16, Andrew G. Malis <agma...@gmail.com<mailto:agma...@gmail.com>> wrote: > > James, Hi Andy, > It's much harder to mandate use of EL than the CW for several reasons: I didn't say it should be mandated, but recommended. > - CW implementation is much more common than EL implementation > - PWs and/or EVPN are rarely the only traffic in an MPLS traffic tunnel, > rather, they will be multiplexed with other MPLS-based applications that are > using the traffic tunnel to reach a common destination. Thus, by using the > CW, you can disable ECMP only for those MPLS packets that cannot tolerate > reordering. The CW does not disable ECMP. Any LSR on the path between ingress and egress LER is free to look beyond the MPLS label stack and misinterpret the 0x00 0x00 at the start of a control-word as a valid MAC that starts 00:00:XX:XX:XX:XX and try to hash on Ethernet headers starting directly after the MPLS label stack, and not label stack + 4 bytes. This is my point. The PWMCW doesn't stop re-ording in all cases, but it does in most. So yes, not all devices support EL, but CW doesn't stop re-ordering in all cases, so? > That said, I'm also concerned that because of the existing text in 7432, > implementations may not be using the CW even for P2P EVPN. > > And we still don't have a good answer for Muthu's original question. :-) Sorry my intention is not to send this thread off-topic. Cheers, James. _________________________________________________________________________________________________________________________ Ce message et ses pieces jointes peuvent contenir des informations confidentielles ou privilegiees et ne doivent donc pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu ce message par erreur, veuillez le signaler a l'expediteur et le detruire ainsi que les pieces jointes. Les messages electroniques etant susceptibles d'alteration, Orange decline toute responsabilite si ce message a ete altere, deforme ou falsifie. Merci. This message and its attachments may contain confidential or privileged information that may be protected by law; they should not be distributed, used or copied without authorisation. If you have received this email in error, please notify the sender and delete this message and its attachments. As emails may be altered, Orange is not liable for messages that have been modified, changed or falsified. Thank you.
_______________________________________________ BESS mailing list BESS@ietf.org https://www.ietf.org/mailman/listinfo/bess
