Re: WGLC for draft-ietf-bfd-large-packets

Robert Raszuk <> Thu, 17 October 2019 07:35 UTC

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From: Robert Raszuk <>
Date: Thu, 17 Oct 2019 09:35:33 +0200
Message-ID: <>
Subject: Re: WGLC for draft-ietf-bfd-large-packets
To: "" <>
Cc: "Les Ginsberg (ginsberg)" <>, "Reshad Rahman (rrahman)" <>, Gyan Mishra <>
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Dear WG,

Thank you Gyan for your note.

It very clearly highlights my primary concern expressed earlier of false
assumptions on how engineers may try to (mis)use bfd-large in multihop

Below note is a brilliant example of how one may not realize that actual
paths BFD packets take can be just a fraction of paths their data plane or
even other control plane packets may traverse over a network or set of

I am always concerned when protocol extensions being standardized are known
to only work in 1 out of 10 deployment scenarios and when chances of such
opportunity of incorrect use are evident yet no safety inline fuse exist.

Many thx,

On Thu, Oct 17, 2019 at 1:29 AM Gyan Mishra <> wrote:

> All,
> I support this draft as I think this would be very useful for IPv6 use
> cases where EH headers are utilized excessively such as for an SRv6 use
> case for traffic engineering over the internet and would be a method to
> test via BFD multihop the path mtu where pmtud has failed to adjust MSS on
> endpoints due to firewalls or other devices dropping ICMP unreachable
> packet to big  messages resulting in 1280 mtu.