Re: [Tsv-art] [v6ops] [Last-Call] Tsvart last call review of draft-ietf-v6ops-ipv6-ehs-packet-drops-05

Fernando Gont <> Tue, 23 February 2021 15:48 UTC

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To: Tom Herbert <>
Cc: Brian E Carpenter <>, Gorry Fairhurst <>,,,, IPv6 Operations <>
References: <> <> <> <> <> <> <> <> <> <> <>
From: Fernando Gont <>
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Date: Tue, 23 Feb 2021 12:26:03 -0300
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Subject: Re: [Tsv-art] [v6ops] [Last-Call] Tsvart last call review of draft-ietf-v6ops-ipv6-ehs-packet-drops-05
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Hi, Tom,

On 23/2/21 11:34, Tom Herbert wrote:
>>From the draft:
> "Unless appropriate mitigations are put in place (e.g., packet
> dropping and/or rate- limiting), an attacker could simply send a large
> amount of IPv6 traffic employing IPv6 Extension Headers with the
> purpose of performing a Denial of Service (DoS) attack"
> That is clearly recommending a mitigation which is to drop packets or
> rate-limit.

No, We're just stating the obvious. If we were performing a 
recommendation, the text would be something like "IPv6 implementations 
should". And we'd also be using RFC2119 speak... and the document would 
be BCP.

> Without any parameterization, this effectively justifies
> routers to arbitrarily drop all packets with any extension headers
> (rate-limiting packets makes the protocol effectively useless). Also,
> if mitigations are being mentioned then the draft should also mention
> the possibility that routers could be fixed, this is particularly
> apropos with regards to the "DoS due to implementation errors".
> Contemporary routers are trending towards being programmable so
> implementation errors should be more amendable to being fixed without
> hardware swap out.

This is document does not provide any sort of advice. It's an analysis 
of which packets may get dropped.

What you are asking could indeed be interesting -- but it's certainly 
out of the scope of this document.

Fernando Gont
SI6 Networks
PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492