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

["Wei Zhou (weizho2)" <[e-mail]>]

Hi, Xiaohu

The motivate for enabling VRRP, rather than IGP in the real transit
network is to address the following scenarios: 1) two PIM domains in
different subnets (possibly with firewall in between), or 2) in a single
subnet where the provider does not wish to run a routing protocol between
the provider's network and customer networks.


Thanks,
Wei





On 5/23/13 6:56 PM, "Xuxiaohu" <[e-mail]> wrote:

>Hi,
>
>> -----邮件原件-----
>> 发件人: Wei Zhou (weizho2) [mailto:[e-mail]]
>> 发送时间: 2013年5月24日 5:36
>> 收件人: Prashant Jhingran (pjhingra); Rajiv Asati (rajiva); Mike McBride;
>> Xuxiaohu; [e-mail]
>> 抄送: Stig Venaas; [e-mail]
>> 主题: Re: [pim] call for adoption: draft-zhou-pim-vrrp-01
>> 
>> Hi,
>> 
>> Thank you all for providing comments and the information on
>> http://tools.ietf.org/html/draft-xu-pim-drpriority-auto-adjustment-03.
>> 
>> I just read through the draft proposed by xiaohu as I was not aware of
>> this draft until xiaohu kindly mentioned in the mail list. After
>>carefully
>> comparing the two drafts, let me try explain the differences between
>>them
>> (referred as draft-xu-dr-adj and draft-zhou-pim-vrrp):
>> 
>> 1. The original problems that two drafts try to solve might look similar
>> but they are actually quite different in the following way:
>> draft-xu-dr-adj targets the PIM DR auto-adjustment based on upstream
>>link
>> tracking, while the idea in draft-zhou-pim-vrrp is to provide a complete
>> solution to enable multicast to interoperate with first hop redundancy
>> protocol in response to any interested events: Master routers goes down,
>> upstream link up/down, bandwidth change and other logical objects that
>> VRRP could track.
>
>As it said in section 2 of draft-xu-dr-adj,
>
>"  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.
>"
>In a word, the PIM DR and the VRRP master could actually run on the same
>router no matter whatever factor triggers the VRRP switchover, as per the
>above description.
>
>> 2. The solution proposed in draft-zhou-pim-vrrp is designed as a
>>complete
>> multicast failover mechanism: in addition to DR priority adjustment, the
>> new draft addresses other critical problems in providing multicast
>> redundancy, including Assert metric adjustment, DF election for BiDir
>> group and tracking multiple VRRP groups.
>
>
>> 3. In addition to last-hop and first-hop scenario, the new draft
>>addresses
>>  transit network scenario to make Master router process PIM J/P for the
>> virtual address, and how to maintain or rebuild J/P state when
>>switching.
>
>Could you please explain the motivation for enabling VRRP, rather than
>IGP in the real transit network scenario?
>
>> The only similarity between the old and new drafts is to make master
>> router the DR, which is obvious way to make desired router DR.
>
>Yes, this is the major motivation for both drafts in my understanding.
>
>Best regards,
>Xiaohu
>
>> Thanks,
>> Wei
>> 
>> 
>> 
>> 
>> 
>> 
>> On 5/23/13 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
>