Greg 

+ Mankamana and Benchon 

....from PIM WG & BESS which owns LSM MVPN mLDP / P2MP TE S-PMSI and MI-PMSI.

We were discussing PIM BFD use case on this BFD WG thread  and  RFC 8562 and 
RFC 8563 covers strictly L3 VPN LSM ( label switched Multicast) LMDT (labeled 
multicast distribution tree) mLDP / P2MP p-tree S-PMSI ( selective constrained 
MDT / Cisco data MDT) MI-PMSI(inclusive MDT for all VRFs) and not Ethernet 
switching LAN based PIM SM BFD.

We have a new draft in the PIM WG PIM DRLB load balancing GDR capability and 
the draft of hashing of ASM PIM RP hash and ASM and SSM S,G hash load balancing 
of traffic across both PIM DR/BDR does significantly help with convergence as 
50/50 LB split but during failover you still have 50% of the traffic that still 
has to reconverge and SPT tree MRIB/MFIB state has to rebuild.  


https://tools.ietf.org/html/draft-ietf-pim-drlb-11


So the BFD PIM Draft would register the PIM protocol and in asynchronous mode 
with echo disabled we can achieve sub millisecond detection time and 
convergence during failover.

So I do think we need a PIM BFD Draft. 

Since this falls between multiple WG but since BFD related this would be under 
the BFD WG.

I am part of the BFD WG as well as part of PIM and BESS so I can assist in 
writing the draft if we are all in agreement that this is needed and can work 
with Mankamana and Benchon as well in creating the draft.

Gyan

Sent from my iPhone

> On Oct 12, 2019, at 12:07 AM, Greg Mirsky <[email protected]> wrote:
> 
> Hi Gyan,
> thank you for your interest in this draft. We've described how RFC 8562 BFD 
> for Multipoint Networks can be used to shorten convergence in PIM-SM. The 
> similar scenario discussed in draft-ietf-bess-mvpn-fast-failover where p2mp 
> BFD is used by tails to detect the failure of the head/root or the multicast 
> tree. If it is required for the head/root to detect a defect of the multicast 
> tree toward a tail, we'll turn to RFC 8563 BFD for Multipoint  Active Tails 
> as in draft-hu-bier-bfd.
> Hope this information would be helpful to you. I always welcome your 
> questions.
> 
> Regards,
> Greg
> 
>> On Fri, Oct 11, 2019 at 7:40 PM Gyan Mishra <[email protected]> wrote:
>> Greg 
>> 
>> I saw your draft on PIM BFD use cases but could not find the RFC on PIM BFD.
>> 
>> 
>> https://tools.ietf.org/id/draft-mirsky-pim-bfd-p2mp-use-case-02.html
>> 
>> Thanks 
>> 
>> Gyan
>> Verizon Communications 
>> Cell-301 502-1347
>> 
>> 
>> Sent from my iPhone
>> 
>>> On Oct 11, 2019, at 9:53 PM, Gyan Mishra <[email protected]> wrote:
>>> 
>>> 
>>> BFD WG
>>> 
>>> Anyone know what the RFC or draft for PIM BFD support.
>>> 
>>> Thank you
>>> 
>>> Gyan 
>>> Verizon Communications 
>>> 
>>> 
>>> 
>>> Sent from my iPhone

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