Weiguo, Since you mention https://tools.ietf.org/html/draft-rabadan-bess-evpn-ac-df-00 let me point at a few differences with your draft:
- In our draft we are NOT using AD routes for the DF election. The DF election is still based on RFC7432. I fully agree with Patrice/John/Satya that doing this handshaking is an unnecessary control plane overhead. It also slows down significantly the DF election process, at the expense of maybe avoiding a few duplicate packets (loops are resolved in the RFC7432) if the timers in RFC7432 were not configured properly. - In our draft, for EVPN, we are not adding any new attribute or modifying the DF election. We are only using the existing information from the AD per-EVI routes to modify the candidate list for a given EVI. But note that those AD routes per-EVI are part of RFC7432 and are sent any way. So our draft is fully compatible with RFC7432 and Satya’s draft. - In your draft, it is not clear if you use AD routes per-ES or per-EVI. a) If it is per-ES, it simply does not work - as John says you need the DF indication per EVI. b) if it is per-EVI then it is a huge overhead as was mentioned below, and those routes get to every PE in the network. - Also in your slides, you also seem to use a timer to allow time to discover the ESI… plus the additional time of sending the DF indication and receiving the DF notification. This is BGP, so assuming you have RRs and the min-route-advertisement-intervals recommended, plus the local additional processing you are introducing, the whole DF election process is significantly slowed down. Thank you. Jorge From: Haoweiguo <[email protected]<mailto:[email protected]>> Date: Thursday, March 26, 2015 at 12:25 PM To: John E Drake <[email protected]<mailto:[email protected]>>, "Patrice Brissette (pbrisset)" <[email protected]<mailto:[email protected]>> Cc: "Ali Sajassi (sajassi)" <[email protected]<mailto:[email protected]>>, "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos algorithm Pls read my detail replies to Satya. If you still can't catch it, pls read my draft and EVPN base protocol, thanks weiguo ________________________________ From: John E Drake [[email protected]<mailto:[email protected]>] Sent: Friday, March 27, 2015 1:28 To: Patrice Brissette (pbrisset) Cc: Haoweiguo; Ali Sajassi (sajassi); [email protected]<mailto:[email protected]> Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos algorithm I think Patrice is correct. Your proposal doesn't solve the problem and it does so at huge cost. Sent from my iPhone On Mar 26, 2015, at 10:34 AM, Patrice Brissette (pbrisset) <[email protected]<mailto:[email protected]>> wrote: Weiguo, I’m not sure I’m following here. Don’t you have the same issue with your handshaking mechanism? If you don’t know your peer, how can you handshake? Regards, Patrice [http://www.cisco.com/web/europe/images/email/signature/est2014/logo_06.png?ct=1406640631632] Patrice Brissette TECHNICAL LEADER.ENGINEERING [email protected]<mailto:[email protected]> Phone: +1 613 254 3336 Cisco Systems Canada Co. / Les Systemes Cisco Canada CIE Canada Cisco.com<http://www.cisco.com/global/CA/> [http://www.cisco.com/assets/swa/img/thinkbeforeyouprint.gif] Think before you print. This email may contain confidential and privileged material for the sole use of the intended recipient. Any review, use, distribution or disclosure by others is strictly prohibited. If you are not the intended recipient (or authorized to receive for the recipient), please contact the sender by reply email and delete all copies of this message. Please click here<http://www.cisco.com/web/about/doing_business/legal/cri/index.html> for Company Registration Information. From: Haoweiguo <[email protected]<mailto:[email protected]>> Date: Thursday, March 26, 2015 at 10:24 AM To: Patrice Brissette <[email protected]<mailto:[email protected]>>, John E Drake <[email protected]<mailto:[email protected]>>, Ali Sajassi <[email protected]<mailto:[email protected]>>, "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: RE: [bess] Handshaking among PEs in an EVPN ES based on Paxos algorithm Hi Patrice, Up to reception timer traffic disruption in transient phase is one of the issues. Thanks, weiguo ________________________________ From: Patrice Brissette (pbrisset) [[email protected]<mailto:[email protected]>] Sent: Thursday, March 26, 2015 20:54 To: Haoweiguo; John E Drake; Ali Sajassi (sajassi); [email protected]<mailto:[email protected]> Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos algorithm Weiguo, You mention "But if your draft have not solved all issues”, Can you explain what Satya’s draft is not solving? Regards, Patrice [http://www.cisco.com/web/europe/images/email/signature/est2014/logo_06.png?ct=1406640631632] Patrice Brissette TECHNICAL LEADER.ENGINEERING [email protected]<mailto:[email protected]> Phone: +1 613 254 3336 Cisco Systems Canada Co. / Les Systemes Cisco Canada CIE Canada Cisco.com<http://www.cisco.com/global/CA/> [http://www.cisco.com/assets/swa/img/thinkbeforeyouprint.gif] Think before you print. This email may contain confidential and privileged material for the sole use of the intended recipient. Any review, use, distribution or disclosure by others is strictly prohibited. If you are not the intended recipient (or authorized to receive for the recipient), please contact the sender by reply email and delete all copies of this message. Please click here<http://www.cisco.com/web/about/doing_business/legal/cri/index.html> for Company Registration Information. From: Haoweiguo <[email protected]<mailto:[email protected]>> Date: Wednesday, March 25, 2015 at 10:38 PM To: John E Drake <[email protected]<mailto:[email protected]>>, Ali Sajassi <[email protected]<mailto:[email protected]>>, "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos algorithm Hi John, Firstly i think EVPN community should reach consensus on the issues of current DF election mechanism. All these issues should be resolved in a single new DF election draft,rather than in multiple separate drafts. If your draft can solve all these issues and stable, i have no question for its progressing. But if your draft have not solved all issues, i think it had better combine with other drafts to provide a comprehensive solution. I think the issues listed in draft-rabadan-bess-evpn-ac-df-01 and draft-hao-bess-evpn-df-handshaking-00 is valid, it should be resolved. So i think although your new Hash algorithm for DF election is good, it only includes partial enhancements, maybe it still needs some time for consensus. Thanks, weiguo ________________________________ From: John E Drake [[email protected]<mailto:[email protected]>] Sent: Thursday, March 26, 2015 7:16 To: Haoweiguo; Ali Sajassi (sajassi); [email protected]<mailto:[email protected]> Subject: RE: [bess] Handshaking among PEs in an EVPN ES based on Paxos algorithm Weiguo, Your proposal introduces a control plane processing load that is O(#EVIs * PEs) per DF election and given that there can be 4K EVIs per ES, this looks like a *substantial* load. Furthermore, you can’t use the ES route to co-ordinate DF election because you would need to carry your new extended community for each EVI and they would not all fit. You also can’t use the Per EVI Ethernet AD route because that is processed by all PEs in the EVI. I think that from a practical perspective the new DF election proposed in Satya’s draft is sufficiently stable that it renders your draft moot, even if it could be made to work. Yours Irrespectively, John From: BESS [mailto:[email protected]] On Behalf Of Haoweiguo Sent: Wednesday, March 25, 2015 5:34 PM To: Ali Sajassi (sajassi); [email protected]<mailto:[email protected]> Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos algorithm Hi Ali, Thanks for your information. I scanned through this draft, it really introduces inter-chassis message for DF election handshaking, the requirements in this draft is to eliminate transiet Loop and traffic duplication. Current EVPN DF election mechanism already eliminated loop and traffic duplication by configuring long reception timer on each multi-homed PE, but up to reception timer traffic disruption issue still exist. EVPN for DCI is an important use case for EVPN, up to reception timer traffic disruption can't be tolerated for service providers, it should be improved. Also for accuracy, i think handshaking state machine on each multi-homed PE is also needed. From solution perspective, in my draft, no inter-chassis message is introduced, only one new extended community is introduced, i think the process is comparatively simple than your following draft. Current EVPN DF election has some drawbacks, so there are three new drafts about DF election emerged. I think BESS WG can consider these three drafts in global view, a single,comprehensive new DF election draft is hoped. thanks. Thanks, weiguo ________________________________ From: BESS [[email protected]<mailto:[email protected]>] on behalf of Ali Sajassi (sajassi) [[email protected]<mailto:[email protected]>] Sent: Thursday, March 26, 2015 0:21 To: [email protected]<mailto:[email protected]> Subject: [bess] Handshaking among PEs in an EVPN ES based on Paxos algorithm FYI- First published July 4, 2011 https://datatracker.ietf.org/doc/draft-sajassi-l2vpn-evpn-segment-route/ -Ali
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