Hi Weiguo, As I said: "Even if CE3 forwards to CE4->PE4, PE4 is NDF and will discard the frame. Remember MH network ES' as per your diagram below, only support single-active MH.”
So there is NO LOOP. If you have any other scenario, let’s talk offline. We are boring people ;-) Thanks. Jorge -----Original Message----- From: Haoweiguo <[email protected]> Date: Friday, March 27, 2015 at 9:00 AM To: Jorge Rabadan <[email protected]>, "Satya Mohanty (satyamoh)" <[email protected]>, "[email protected]" <[email protected]>, "[email protected]" <[email protected]> Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos algorithm >Hi Jorge, >The picture in email is just for a simplified explanation. Source MAC can >be the layer 3 device connecting to CE3, CE3 will not drop the frame so >easily. This is an absolutely loop. > >Thanks, >weiguo > >________________________________________ >From: Rabadan, Jorge (Jorge) [[email protected]] >Sent: Friday, March 27, 2015 23:39 >To: Haoweiguo; Satya Mohanty (satyamoh); [email protected]; >[email protected] >Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos >algorithm > >Hi Weiguo, > >I disagree with your explanation below. > >This is the flow assuming PE1-PE2 *might* be both DF and PE3 is DF: > >CE3--->PE3------>PE2--->CE2---->CE1---->PE1---->PE3-->CE3——>DROP > >If the MAC SA of the frame is CE3’s MAC, CE3 will discard. >Even if CE3 forwards to CE4->PE4, PE4 is NDF and will discard the frame. >Remember MH network ES' as per your diagram below, only support >single-active MH. > > >Thanks. >Jorge > >-----Original Message----- >From: Haoweiguo <[email protected]> >Date: Friday, March 27, 2015 at 8:11 AM >To: Jorge Rabadan <[email protected]>, "Satya Mohanty >(satyamoh)" <[email protected]>, "[email protected]" ><[email protected]>, "[email protected]" <[email protected]> >Subject: RE: [bess] Handshaking among PEs in an EVPN ES based on Paxos >algorithm > >>Hi Jorge, >>Let give you another indefinitely forwarding loop case, the picture is as >>follows: >> >>CE3------------CE4 >> | | >>PE3 PE4 >> >> >> >>PE1 PE2 >> | | >>CE1------------CE2 >> >>If PE1 and PE2 are dual DF PE in transiet time, assuing PE3 and PE4 are >>in stable state ,PE3 is DF PE, PE4 is non-DF PE, the BUM traffic from CE3 >>to CE1, the forwarding loop path is as follows; >>CE3--->PE3------>PE2--->CE2---->CE1---->PE1---->PE3-->CE3-->CE4--->PE4--- >>- >>>forever...... >> >>Do you think the harm is enough? >>Thanks, >>weiguo >>________________________________________ >>From: Rabadan, Jorge (Jorge) [[email protected]] >>Sent: Friday, March 27, 2015 22:59 >>To: Haoweiguo; Satya Mohanty (satyamoh); [email protected]; >>[email protected] >>Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos >>algorithm >> >>Hi Weiguo, >> >>OK, thanks for clarifying, that is the part I did not understand in your >>loop :-) >> >>To me a loop means you send a frame and that frame keeps being forwarded >>by the same nodes indefinitely till you take a corrective action. >>In this case, CE3 might get a few packets during the transient state, but >>those packets will have its own MAC SA so CE3 will discard them. I don’t >>think that is harmful for CE3 in most of the cases. And if it is, you >>just >>need to make sure the timers are long enough and the DF election properly >>implemented to avoid the transient DF-DF state. >> >>The handshaking is definitely overkilling IMHO. >> >>Thanks. >>Jorge >> >>-----Original Message----- >>From: Haoweiguo <[email protected]> >>Date: Friday, March 27, 2015 at 7:29 AM >>To: Jorge Rabadan <[email protected]>, "Satya Mohanty >>(satyamoh)" <[email protected]>, "[email protected]" >><[email protected]>, "[email protected]" <[email protected]> >>Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos >>algorithm >> >>>Hi Jorge, >>>Sorry, maybe i have not explain clearly, pls allow me to clarify it more >>>clearly. >>>In MHN case, assuming CE1 and CE2 are multti-homed to PE1 and PE2, CE2 >>>is >>>single homed to remote PE3. CE1 and CE2 forms one layer 2 network, so it >>>multi-homed network scenario. >>> CE3 >>> | >>> PE3 >>> >>> >>>PE1 PE2 >>> | | >>>CE1-----------CE2 >>> >>>In transiet period, PE1 and PE2 are both DF PE. At this time, CE3 sends >>>BUM traffic to CE1, the traffic will reach PE1 and PE2, CE1 will receive >>>two copy of the traffic from CE3, also loop is formed, the form path: >>> >>>CE3---->PE3---->PE2---->CE2---->CE1---->PE1--->PE3--->CE3 >>> >>>I think the traffic loop is absolutely not allowed. In MHN case, the >>>loop >>>will formed due to dual-DF PE in transiet period. >>> >>>Thanks, >>>weiguo >>> >>> >>> >>>________________________________________ >>>From: Rabadan, Jorge (Jorge) [[email protected]] >>>Sent: Friday, March 27, 2015 20:26 >>>To: Haoweiguo; Satya Mohanty (satyamoh); [email protected]; >>>[email protected] >>>Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos >>>algorithm >>> >>>Hi Weiguo, >>> >>>About this: >>> >>>[weiguo]: Traffic duplication and loop issue both exist in dual DF PE >>>case. In multi-homed device case, say CE1 is multi-homed to PE1 and PE2 >>>and both PE are DF PE. When CE1 sends traffic to PE1, the traffic will >>>loop back to CE1 through PE2. If CE1 can filter and drop the traffic , >>>it >>>is fortunate, maybe no loop. >>>For multi-homed network scenario, say local network1(CE1 and CE2) is >>>multi-homed to PE1 and PE2. Similarly, the traffic from CE1 will loop >>>back >>>through PE1-->PE2-->CE2, it is very serious. It is absolutely not >>>allowed. >>> >>> >>>[JORGE] In a MH device case: CE1->BUM->PE1->(ESI-label+BUM)->PE2. PE2 >>>will >>>not send the traffic back to CE1 due to the ESI-label and split-horizon >>>procedures. >>>In MH network case PE2 will NOT send the traffic to CE2 for the same >>>reason. >>> >>>Let me know if you disagree please. >>> >>>Thanks. >>>Jorge >>> >>>-----Original Message----- >>>From: Haoweiguo <[email protected]> >>>Date: Thursday, March 26, 2015 at 9:55 PM >>>To: "Satya Mohanty (satyamoh)" <[email protected]>, >>>"[email protected]" <[email protected]>, "[email protected]" >>><[email protected]> >>>Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos >>>algorithm >>> >>>>Hi Satya, >>>>Pls see inline. >>>> >>>>Thanks, >>>>weiguo >>>> >>>>________________________________________ >>>>From: Satya Mohanty (satyamoh) [[email protected]] >>>>Sent: Friday, March 27, 2015 12:11 >>>>To: Haoweiguo; [email protected]; [email protected] >>>>Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos >>>>algorithm >>>> >>>>Thomas, >>>> >>>>Thanks for your summary. It captures the essence of the discussion. >>>>[weiguo]: Yes, i agree. >>>> >>>>One feature of the HRW scheme is that it computes the Active and the >>>>Backup DF upfront. >>>>Whenever the Active PE, say PE1, dies; >>>>the Backup PE, PE2, can become the >>>>Active immediately upon receiving the withdraw of the ES route from >>>>PE1. >>>>It need not even have to wait for the 3 seconds time. >>>>[weiguo]: I think maybe your negligence, dies PE1 can't send withdraw >>>>message:) But when PE1 leaves ESI, it can withdraw the ES route >>>>immediately. >>>>When PE1 dies and recovers, assuming PE1 is DF PE, then PE1 and PE2 >>>>will >>>>both act as PE for some transiet time. >>>> >>>>On the other hand, the 3 second timer will serve as a bulk and batch >>>>mechanism for the case when new PE(s) is(are) coming up, so we don¹t >>>>have >>>>to do a DF election ever so often. >>>> >>>>Haoweiguo, I think the "loop" scenario is speculative. >>>>I think everybody understands that, yes, there may be some transient >>>>duplication of bum traffic; however, there is no "loop" problem to be >>>>solved. >>>>[weiguo]: Traffic duplication and loop issue both exist in dual DF PE >>>>case. In multi-homed device case, say CE1 is multi-homed to PE1 and PE2 >>>>and both PE are DF PE. When CE1 sends traffic to PE1, the traffic will >>>>loop back to CE1 through PE2. If CE1 can filter and drop the traffic , >>>>it >>>>is fortunate, maybe no loop. >>>>For multi-homed network scenario, say local network1(CE1 and CE2) is >>>>multi-homed to PE1 and PE2. Similarly, the traffic from CE1 will loop >>>>back through PE1-->PE2-->CE2, it is very serious. It is absolutely not >>>>allowed. >>>> >>>>Thanks, >>>>--Satya >>>> >>>> >>>> >>>>On 3/26/15 9:08 PM, "Haoweiguo" <[email protected]> wrote: >>>> >>>>>Hi Thomas, >>>>>I know you are neutral, sorry for my reply vulnerable to be >>>>>miunderstood. >>>>> >>>>>Thanks, >>>>>weiguo >>>>> >>>>>________________________________________ >>>>>From: [email protected] [[email protected]] >>>>>Sent: Friday, March 27, 2015 11:59 >>>>>To: Haoweiguo; [email protected] >>>>>Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos >>>>>algorithm >>>>> >>>>>Hi Weiguo, >>>>> >>>>>2015-03-26, Haoweiguo: >>>>> > Thomas: >>>>>> > - RFC7432 may have transient periods where the DF election state >>>>>>is >>>>>> > not yet synchronized between the two peers: >>>>> > >>>>>> [weiguo]: Yes, i think RFC 7432 has transient periods of traffic >>>>>>loop >>>>> >>>>>Note well that I didn't write that there can be transient _loops_ . >>>>>I tried to capture the exchange you had all, and what I gather is that >>>>>the split-horizon procedure _prevents_loops_, independently of any >>>>>transient period where DF state is not synchronized and which may lead >>>>>to transient _duplicates_. >>>>> >>>>>-Thomas >>>>> >>>>>> >>>>>> 26/03/2015 20:05, John E Drake : >>>>>>> >>>>>>> Weiguo, >>>>>>> >>>>>>> I guess I wasn¹t clear. I think you draft, for the reasons I have >>>>>>> detailed, is a non-solution to a non-problem with tremendous >>>>>>>control >>>>>>> plane cost. >>>>>>> >>>>>>> Yours Irrespectively, >>>>>>> >>>>>>> John >>>>>>> >>>>>>> *From:*Haoweiguo [mailto:[email protected]] >>>>>>> *Sent:* Thursday, March 26, 2015 6:17 PM >>>>>>> *To:* John E Drake; Patrice Brissette (pbrisset) >>>>>>> *Cc:* Ali Sajassi (sajassi); [email protected] >>>>>>> *Subject:* RE: [bess] Handshaking among PEs in an EVPN ES based on >>>>>>> Paxos algorithm >>>>>>> >>>>>>> Pls see below. >>>>>>> >>>>>>> Thanks, >>>>>>> >>>>>>> weiguo >>>>>>> >>>>>>> >>>>>>>-------------------------------------------------------------------- >>>>>>>- >>>>>>>- >>>>>>>- >>>>>>>- >>>>>>> >>>>>>> *From:*John E Drake [[email protected]] >>>>>>> *Sent:* Friday, March 27, 2015 6:00 >>>>>>> *To:* Haoweiguo; Patrice Brissette (pbrisset) >>>>>>> *Cc:* Ali Sajassi (sajassi); [email protected] <mailto:[email protected]> >>>>>>> *Subject:* RE: [bess] Handshaking among PEs in an EVPN ES based on >>>>>>> Paxos algorithm >>>>>>> >>>>>>> To recap, >>>>>>> >>>>>>> We have established that your proposal is untenable because of its >>>>>>> control plane load. >>>>>>> >>>>>>> We have established that your proposal is based upon a flawed >>>>>>> understanding of the DF election in RFC 7432. >>>>>>> >>>>>>> [weiguo]: In ethernet world, traffic loop is serious than short >>>>>>>timer >>>>>>> traffic disruption. If you want to implement transiet traffic loop >>>>>>> process, i will modify my draft to solve your issue. >>>>>>> >>>>>>> If i am the developer, i will prefer short timer traffic disruption >>>>>>> based on current EVPN protocol. >>>>>>> >>>>>>> What you are now arguing is that your draft prevents two or more >>>>>>>PEs >>>>>>> from being DF simultaneously. This is clearly nonsense. >>>>>>> >>>>>>> [weiguo]: I will modify the draft problem statements, and use the >>>>>>>same >>>>>>> handshaking solution to solve it. >>>>>>> >>>>>>> Furthermore, we have established that having two or more DFs for >>>>>>>what >>>>>>> even you admit is a brief transient leads to duplicate traffic, >>>>>>>which >>>>>>> is acceptable, but not loops, your assertion to the contrary. >>>>>>> >>>>>>> [weiguo]: It is transient loop and traffic duplication issue. >>>>>>> >>>>>>> Yours Irrespectively, >>>>>>> >>>>>>> John >>>>>>> >>>>>>> *From:*Haoweiguo [mailto:[email protected]] >>>>>>> *Sent:* Thursday, March 26, 2015 5:37 PM >>>>>>> *To:* John E Drake; Patrice Brissette (pbrisset) >>>>>>> *Cc:* Ali Sajassi (sajassi); [email protected] <mailto:[email protected]> >>>>>>> *Subject:* RE: [bess] Handshaking among PEs in an EVPN ES based on >>>>>>> Paxos algorithm >>>>>>> >>>>>>> John, >>>>>>> >>>>>>> As your understanding of the EVPN draft, the DF election mechanism >>>>>>>has >>>>>>> more serious side effect, it will have short time traffic >>>>>>>loop,i.e., >>>>>>> dual DF PEs will exist for a short time. I think dual DF PEs is >>>>>>> absolutely not tolerated, because native ethernet header has no >>>>>>>TTL, >>>>>>> up to several hundred ms traffic loop normally not tolerated in >>>>>>> commertial networks. >>>>>>> >>>>>>> As your understanding, the PEs should do as following: >>>>>>> >>>>>>> 1. Accurate timer sync. NTP accuracy is bad, 1588v2 is good but >>>>>>>have >>>>>>> rarely deployment. >>>>>>> >>>>>>> Assuming PE1,PE2 and PE3 have consistent timer clock, when PE3 >>>>>>>joins >>>>>>> ESI and trigger DF re-election. When reception timer expires: >>>>>>> >>>>>>> PE1 upgrades to DF PE. >>>>>>> >>>>>>> After reception timer+ ES route transmission timer: >>>>>>> >>>>>>> PE2 downloads to non-DF PE. >>>>>>> >>>>>>> So in timer clock sync case, dual DF PEs will exist at least >>>>>>> transmission timer. >>>>>>> >>>>>>> If NTP is used for timer sync, because it has bad accuracy, dual DF >>>>>>> PEs will exist more longer timer. >>>>>>> >>>>>>> So as your understanding for DF election, the drawback is more >>>>>>>clear. >>>>>>> >>>>>>> Thanks, >>>>>>> >>>>>>> weiguo >>>>>>> >>>>>>> >>>>>>>-------------------------------------------------------------------- >>>>>>>- >>>>>>>- >>>>>>>- >>>>>>>- >>>>>>> >>>>>>> *From:*John E Drake [[email protected]] >>>>>>> *Sent:* Friday, March 27, 2015 4:41 >>>>>>> *To:* Haoweiguo; Patrice Brissette (pbrisset) >>>>>>> *Cc:* Ali Sajassi (sajassi); [email protected] <mailto:[email protected]> >>>>>>> *Subject:* RE: [bess] Handshaking among PEs in an EVPN ES based on >>>>>>> Paxos algorithm >>>>>>> >>>>>>> Weiguo, >>>>>>> >>>>>>> We have already established that your proposal is untenable because >>>>>>>of >>>>>>> its control plane load. >>>>>>> >>>>>>> What we are now discussing is that your proposal is based upon a >>>>>>> misunderstanding of the algorithm in RFC 7432. You are assuming >>>>>>>that >>>>>>> PE1 will advertise an ES route and then wait for the configured >>>>>>> interval before performing the DF election while PE2 and PE3 will >>>>>>> perform the DF election as soon as they receive the ES route from >>>>>>>PE1. >>>>>>> This is not what RFC 7432 says. >>>>>>> >>>>>>> Rather, what is says is that the advertisement of the ES route by >>>>>>>PE1 >>>>>>> and its receipt by PE2 and PE3 causes all three PEs to start the >>>>>>> configured interval timer - ³3. When the timer expires, each PE >>>>>>> builds an ordered list of the IP addresses of all the PE nodes >>>>>>> connected to the Ethernet segment (including itself), in increasing >>>>>>> numeric value.² >>>>>>> >>>>>>> Yours Irrespectively, >>>>>>> >>>>>>> John >>>>>>> >>>>>>> *From:*Haoweiguo [mailto:[email protected]] >>>>>>> *Sent:* Thursday, March 26, 2015 3:26 PM >>>>>>> *To:* John E Drake; Patrice Brissette (pbrisset) >>>>>>> *Cc:* Ali Sajassi (sajassi); [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]] >>>>>>> *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, >>>>>>> >>>>>>> I¹m not sure I¹m following here. >>>>>>> >>>>>>> Don¹t you have the same issue with your handshaking mechanism? >>>>>>> >>>>>>> If you don¹t know your peer, how can you handshake? >>>>>>> >>>>>>> Regards, >>>>>>> >>>>>>> Patrice >>>>>>> >>>>>>> Image removed by sender. >>>>>>> >>>>>>> *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/> >>>>>>> >>>>>>> >>>>>>> >>>>>>> Image removed by sender.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 >>>>>>>issues², >>>>>>> >>>>>>> Can you explain what Satya¹s draft is not solving? >>>>>>> >>>>>>> Regards, >>>>>>> >>>>>>> Patrice >>>>>>> >>>>>>> Image removed by sender. >>>>>>> >>>>>>> *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/> >>>>>>> >>>>>>> >>>>>>> >>>>>>> Image removed by sender.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 can¹t 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 can¹t 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 Satya¹s 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-ro >>>>>>>u >>>>>>>t >>>>>>>e >>>>>>>/ >>>>>>> >>>>>>> -Ali >>>>>>> >>>>>>> >>>>>>> >>>>>>> _______________________________________________ >>>>>>> BESS mailing list >>>>>>> [email protected] >>>>>>> https://www.ietf.org/mailman/listinfo/bess >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>>_____________________________________________________________________ >>>>>>_ >>>>>>_ >>>>>>_ >>>>>>_ >>>>>>________________________________________________ >>>>>> >>>>>> 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 >>>>>> [email protected] >>>>>> https://www.ietf.org/mailman/listinfo/bess >>>>>> >>>>> >>>>> >>>>>______________________________________________________________________ >>>>>_ >>>>>_ >>>>>_ >>>>>_ >>>>>_______________________________________________ >>>>> >>>>>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. 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