Re: [pim] call for adoption: draft-zhou-pim-vrrp-01

[Xuxiaohu <[e-mail]>]

Hi Wei,

> -----邮件原件-----
> 发件人: Wei Zhou (weizho2) [mailto:[e-mail]]
> 发送时间: 2013年6月7日 1:23
> 收件人: Xuxiaohu; Mike McBride; Prashant Jhingran (pjhingra)
> 抄送: Rajiv Asati (rajiva); [e-mail]; Stig Venaas;
> [e-mail]
> 主题: Re: [pim] call for adoption: draft-zhou-pim-vrrp-01
> 
> Hi Xiaohu,
> 
> Actually I would say it is not true that the new draft is "irrelevant" to
> upstream link failure, which is one of the many scenarios that the new
> general solution is trying to address.

What are the other scenarios that the general solution is trying to address?
 
> If customer runs an IGP, then upstream failure is not an issue. On the
> other hand if people want to they can configure VRRP to track link
> failures, but that was not the focus of the new draft. Discussing the
> different objects that different VRRP implementations may allow users to
> track is not one of the purposes of the new draft, as that is not needed
> to explain how VRRP interacts with PIM.
> 
> Moreover, it is definitely true that the new draft is proposing to make
> PIM DR and VRRP Master run on the same router by adjusting PIM DR
> priority, which I believe is the obvious way to make PIM respond to VRRP
> state change and something both drafts support. If you have new/different
> thoughts on this, please share.
> 
> So in addition to that obvious part shared by both drafts, may I know what
> technical content/details you'd suggest to merge between the two drafts?

IMHO, that "obvious" part is the only practical problem that needs to be solved. The transit LAN scenario is a fake one, which has been explained in a previous email.

Best regards,
Xiaohu
 
> Thanks,
> Wei
> 
> 
> 
> 
> 
> 
> On 6/4/13 8:19 PM, "Xuxiaohu" <[e-mail]> wrote:
> 
> >Hi Wei,
> >
> >> -----邮件原件-----
> >> 发件人: Wei Zhou (weizho2) [mailto:[e-mail]]
> >> 发送时间: 2013年6月1日 2:56
> >> 收件人: Mike McBride; Prashant Jhingran (pjhingra)
> >> 抄送: Rajiv Asati (rajiva); Xuxiaohu; [e-mail]; Stig
> >> Venaas; [e-mail]
> >> 主题: Re: [pim] call for adoption: draft-zhou-pim-vrrp-01
> >>
> >> Hi,
> >>
> >> Thank you all for the comments and thoughts. I believe that the old
> >>draft
> >> is about upstream link failures, which is not what the new draft is
> >>about.
> >> The new draft is about how to support PIM and VRRP in general instead of
> >> focusing on the object being tracked.
> >
> >If your draft is irrelevant to upstream link failure scenario, what's the
> >motivation for making the PIM DR and the VRRP master always run on the
> >same router? In other words, what's the problem when the PIM DR doesn't
> >run on the VRRP master router? It seems that the below text quoted from
> >your draft doesn't really state the FINAL problem. IMHO, it doesn't
> >matter whether or not the multicast traffic is forwarded by the VRRP
> >master router. In addition, "to ensure that the PIM DR is always able to
> >forward PIM Join/Prune message towards RP or FHR", it doesn't require the
> >PIM DR runs on the VRRP master router either.
> >
> >===============================
> >  "PIM has no inherent redundancy capabilities and its operation is
> >   completely independent of VRRP group states.  As a result, IP
> >   multicast traffic is forwarded not necessarily by the same device as
> >   is elected by VRRP.  The VRRP Aware PIM feature provides consistent
> >   IP multicast forwarding in a redundant network with virtual routing
> >   groups enabled.
> >
> >   In a multi-access segment (such as LAN), PIM designated router (DR)
> >   election is unaware of the redundancy configuration, and the elected
> >   DR and VRRP master router (MR) may not be the same router.  In order
> >   to ensure that the PIM DR is always able to forward PIM Join/Prune
> >   message towards RP or FHR, the VRRP MR becomes the PIM DR (if there
> >   is only one VRRP group)...."
> >===============================
> >
> >Best regards,
> >Xiaohu
> >
> >> If the WG think the upstream link failure scenario should be discussed
> >>in
> >> detail in the new draft, then I'm completely fine with merging.
> >>Moreover,
> >> if the new draft is adopted in its current shape, then the WG can always
> >> decide to include the upstream link failure scenario later.
> >>
> >> Thanks,
> >> Wei
> >>
> >>
> >>
> >>
> >>
> >> On 5/31/13 12:06 AM, "Mike McBride" <[e-mail]> wrote:
> >>
> >> >Thank you for the responses.
> >> >
> >> >Some feel the two drafts are completely unrelated while others feel
> >> >they are completely related. In either case, are you, who feel they
> >> >are related, saying you oppose the adoption of draft-zhou-pim-vrrp-01?
> >> >We can infer that is the case but I haven't heard explicitly stated
> >> >opposition to adoption. We now have several choices for
> >> >draft-zhou-pim-vrrp, let me try boiling it down to 3:
> >> >
> >> >1. adopt draft-zhou-pim-vrrp-01 as is
> >> >2. adopt draft-zhou-pim-vrrp-01 only after
> >> >draft-xu-pim-drpriority-auto-adjustment is referenced.
> >> >3. merge the drafts
> >> >
> >> >In either case the authors should revive the expired
> >> >draft-xu-pim-drpriority-auto-adjustment-03 for consideration within
> >> >the wg irregardless of vrrp-01 adoption outcome.
> >> >
> >> >What say ye?
> >> >
> >> >mike
> >> >
> >> >On Thu, May 23, 2013 at 2:08 AM, Prashant Jhingran (pjhingra)
> >> ><[e-mail]> wrote:
> >> >> Hi Mike,
> >> >>
> >> >> I agree with Rajiv, both drafts are trying to solve the same
> >> >>issue....that too in almost similar way.
> >> >>
> >> >> -
> >> >> Regards,
> >> >> Prashant Jhingran
> >> >> NOSTG TME - SP Wi-Fi
> >> >>
> >> >> http://wwwin.cisco.com/ios/tech/mobile/proxyipv6/
> >> >> http://wwwin.cisco.com/ios/tech/broadband
> >> >>
> >> >>
> >> >> -----Original Message-----
> >> >> From: Rajiv Asati (rajiva)
> >> >> Sent: Thursday, May 23, 2013 3:06 AM
> >> >> To: Mike McBride; Xuxiaohu; [e-mail];
> Prashant
> >> >>Jhingran (pjhingra); Wei Zhou (weizho2)
> >> >> Cc: Stig Venaas; [e-mail]
> >> >> Subject: RE: [pim] call for adoption: draft-zhou-pim-vrrp-01
> >> >>
> >> >> Hi Mike,
> >> >>
> >> >> It seems that both drafts seem to solve nearly the same problem
> >> >>(multiple routers on the multi-access interface and existence of
> >> >>first-hop redundancy protocols e.g. VRRP).
> >> >>
> >> >> Cheers,
> >> >> Rajiv
> >> >>
> >> >>
> >> >>> -----Original Message-----
> >> >>> From: Mike McBride [mailto:[e-mail]]
> >> >>> Sent: Wednesday, May 22, 2013 2:17 AM
> >> >>> To: Xuxiaohu; [e-mail]; Rajiv Asati (rajiva);
> >> >>> Prashant Jhingran (pjhingra); Wei Zhou (weizho2)
> >> >>> Cc: Stig Venaas; Mike McBride; [e-mail]
> >> >>> Subject: Re: [pim] call for adoption: draft-zhou-pim-vrrp-01
> >> >>>
> >> >>> Folks,
> >> >>>
> >> >>> We have this new draft-zhou-pim-vrrp-01 which we are about to adopt
> >> >>> into the pim wg. It has been brought to the WGs attention that there
> >> >>> is a older draft (draft-xu-pim-drpriority-auto-adjustment-03) which
> >> >>> may have some overlap with the new one. That older draft does
> >>contain
> >> >>> information about VRRP aware PIM which is attributed to Stig in the
> >> >>> acknowledgements. If the five of you authors feel that there is some
> >> >>> validity that the older draft contains some information being used
> >>in
> >> >>> the new draft, you may want to acknowledge that in the references or
> >> >>> acknowledgements. It appears the drafts are dissimilar enough to not
> >> >>> be merged but I may be wrong. Please share your opinions on this so
> >>we
> >> >>> can establish consensus within the group and move the document
> >>along.
> >> >>>
> >> >>> If the broader WG participants have an opinion on this please speak
> >>up.
> >> >>>
> >> >>> thanks,
> >> >>> mike
> >> >>>
> >> >>> On Thu, May 9, 2013 at 7:32 PM, Xuxiaohu <[e-mail]>
> >> wrote:
> >> >>> > Hi all,
> >> >>> >
> >> >>> > This draft reminds me that there has been a draft
> >> >>>
> >>(http://tools.ietf.org/html/draft-xu-pim-drpriority-auto-adjustment-03
> >> >>> ) three years before which uses almost the same technology to save
> >> >>> almost the same problem.
> >> >>> >
> >> >>> > The following is quoted from the above draft:
> >> >>> >
> >> >>> >    "In fact, if VRRP is run on the PIM routers and the VRRP has
> >> >>>enabled
> >> >>> >    the upstream link tracking mechanism, the PIM DR failover
> >> >>>mechanism
> >> >>> >    could be coupled with the VRRP so as to reuse the upstream link
> >> >>> >    tracking mechanism of VRRP. One option is to synchronize the
> >>PIM
> >> >>>DR
> >> >>> >    priority value to the VRRP priority value always. In this way,
> >>the
> >> >>> >    PIM DR and the VRRP master will always run on an identical
> >>router
> >> >>>if
> >> >>> >    the VRRP Preempt_Mode is set to True. Another option is to
> make
> >> >>>the
> >> >>> >    PIM DR and the VRRP master run on an identical router anyway
> >> >>>(i.e.,
> >> >>> >    regardless whether or not the VRRP Preempt_Mode is True). To
> >> >>>achieve
> >> >>> >    this goal, the PIM DR priority of the VRRP master router SHOULD
> >> >>> >    always be set to a higher fixed value than that of the VRRP
> >>slave
> >> >>> >    router automatically."
> >> >>> >
> >> >>> > Best regards,
> >> >>> > Xiaohu
> >> >>> >
> >> >>> >> -----邮件原件-----
> >> >>> >> 发件人: [e-mail] [mailto:[e-mail]] 代表
> >> >>> Mike
> >> >>> >> McBride
> >> >>> >> 发送时间: 2013年5月10日 3:48
> >> >>> >> 收件人: [e-mail]
> >> >>> >> 主题: [pim] call for adoption: draft-zhou-pim-vrrp-01
> >> >>> >>
> >> >>> >> draft-zhou-pim-vrrp-01 was presented in our most recent pim
> >>meeting
> >> >>> >> in Orlando. 4 people were in favor of adopting the draft. Zero
> >> >>>against.
> >> >>> >> Please read the draft (its short) and provide an opinion either
> >>way
> >> >>> >> by the end of next Friday the 17th.
> >> >>> >>
> >> >>> >> http://www.ietf.org/id/draft-zhou-pim-vrrp-01.txt
> >> >>> >>
> >> >>> >> thanks,
> >> >>> >> mike
> >> >>> >> _______________________________________________
> >> >>> >> pim mailing list
> >> >>> >> [e-mail]
> >> >>> >> https://www.ietf.org/mailman/listinfo/pim
> >