Subject: Re: [Idr] WG adoption call for draft-haas-idr-bfd-subcode-00.txt - Ends 02/04/2022

From: Aijun Wang <[email-masked]>
Date: Sat, 22 Jan 2022 08:34:17 +0800

Hi, Acee:

When the RR sits in, the BFD session for BGP can’t detect the remote Peer’s down.

If possible, I am considering adding another sub-code-“Prefix Unreachable Announcement” :)

Aijun Wang
China Telecom

> On Jan 22, 2022, at 08:05, Acee Lindem (acee) <[email-masked]> wrote:
> 
> Even faster than a speeding Prefix Unreachable Advertisement…
> Acee
>  
> From: Idr <[email-masked]> on behalf of Jeff Haas <[email-masked]>
> Date: Friday, January 21, 2022 at 6:57 PM
> To: Aijun Wang <[email-masked]>
> Cc: Keyur Patel <[email-masked]>, IDR List <[email-masked]>
> Subject: Re: [Idr] WG adoption call for draft-haas-idr-bfd-subcode-00.txt - Ends 02/04/2022
>  
> Aijun,
>  
> BFD can have very quick timers compared to BGP and TCP. Consider the case where BFD is running between two systems with an interval of 50ms and a detection multiplier of 3. 
>  
> 150ms of link loss will cause BFD to go down. 
>  
> BGP and TCP operating at much longer time lines might need a retransmission or two for the same event, if anything at all can be noticed. 
>  
> This discrepancy between what BGP can notice and leave the session up enough to send messages and BFD going down fast often can lead operators to need to figure out what the root cause is. This notification message helps standardize a method to report when BFD is that root cause. 
>  
>  
> 
> Jeff
> 
> 
> On Jan 21, 2022, at 6:47 PM, Aijun Wang <[email-masked]> wrote:
> 
> Hi, Jeffrey:
>  
> Would you like to illustrate the scenarios that “when the BFD session is in DOWN state, but the BGP speakers can send out the NOTIFICATION messages to the remote peer? “ Also what you mentioned in your draft as “partial loss of connection”.
>  
>  
> Aijun Wang
> China Telecom
> 
> 
> On Jan 22, 2022, at 07:01, Keyur Patel <[email-masked]> wrote:
> 
> Hi Folks:
>  
> This is a Working Group adoption call for draft-haas-idr-bfd-subcode-00, “BGP Cease Notification Subcode for BFD”.  Please reply to the list with your comments. This adoption call will conclude on February 4th, 2022.
>  
> The draft can be found at: https://datatracker.ietf.org/doc/draft-haas-idr-bfd-subcode/.
>  
> Best Regards,
> Keyur
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