Re: Mirja Kühlewind's Discuss on draft-ietf-bfd-multipoint-18: (with DISCUSS)

Greg Mirsky <> Thu, 05 July 2018 21:16 UTC

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From: Greg Mirsky <>
Date: Thu, 05 Jul 2018 14:15:33 -0700
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Subject: Re: Mirja Kühlewind's Discuss on draft-ietf-bfd-multipoint-18: (with DISCUSS)
To: "Mirja Kuehlewind (IETF)" <>
Cc: Reshad Rahman <>,,, The IESG <>,
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Hi Mirja,
thank you for the clarification. I believe that the required action and use
of MUST, in this case, is too strong as it defeats the purpose of FM OAM by
hiding the problem rather than detecting and signaling it.


On Thu, Jul 5, 2018 at 1:26 PM, Mirja Kuehlewind (IETF) <
> wrote:

> Hi Greg,
> just one thing quickly
> > Am 05.07.2018 um 21:27 schrieb Greg Mirsky <>:
> >
> > 2) See sec 7 of RFC 8085
> > "When BFD is used across multiple hops, a congestion control mechanism
> >    MUST be implemented, and when congestion is detected, the BFD
> >    implementation MUST reduce the amount of traffic it generates. "
> > GIM>> I couldn't find this in RFC 8085 and had to broaden my search. I
> believe that thsi quote is from RFC 7880 Seamless BFD. I'm puzzled why this
> specification, when talking about challenges S-BFD may face, switches to
> requirement for BFD. Doesn't look right. And more, increasing transmission
> interval to avoid packet drop defeats the purpose of using proactive defect
> detection mechanism. The purpose of the fault management is to detect
> failures, not to avoid the detection. If active OAM generates excess of
> traffic, then other OAM mechanisms can be considered and used. But
> loosening OAM is not, in my view, proper way to address network problem as
> it rather hides them, not detets and reports as it intended to do.
> This quote is from RFC5880. The BFD base spec. Sorry that was copy and
> past error!