Re: [v6ops] Operational Implications of IPv6 Packets with Extension Headers

Fernando Gont <> Mon, 21 September 2020 22:53 UTC

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To: Gyan Mishra <>
Cc: IPv6 Operations <>
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From: Fernando Gont <>
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Date: Mon, 21 Sep 2020 12:18:53 -0300
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Subject: Re: [v6ops] Operational Implications of IPv6 Packets with Extension Headers
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On 19/9/20 16:52, Gyan Mishra wrote:
>     In that sense, RFC6564 is unable to make any difference. Whether
>     providing such feature (common EH format for all EHs, from now on)
>     would
>     have made a difference, is hard to tell... But I'd argue it wouldn't.
>      So bottom line we don’t think there is any operational impact 
> related to eh drops due to operators filtering based on the catch-22 
> issue regarding hardware not being able to support the new EH TLV based 
> standard RFC 6584 to support “new extension headers” supporting new TLV 
> as we believe that new are maybe few and far between that bucket that 
> can impact fast path eh processing. 

I'm just saying that I don't think RFC6564 will have any sort of impact, 
for worse or better.

> Based on the above we believe that 
> we are in that same boat as with eh headers use the same protocol number 
> name space thus impossible to have a complete list so not being able to 
> be processed.


I'm saying that you cannot parse something that you don't know what it 
is. RFC6564 does not change that in any way.

> Also from that perspective as well is not a reason for operators to drop 
> ant eh and an idea is to maybe just explicitly permit all the original 
> RFC 8200 standard eh and new RFC 6584 eh headers as a recommendation to 
> not just drop hbh and other headers that could end up being processed in 
> the slow path.  So instead of doing a drop xyz header followed by a 
> permit any you explicitly permit all RFC 8200 and RFC 6584 headers If 
> your platform supports.

Please see draft-ietf-v6ops-ipv6-ehs-packet-drops. :-)

Fernando Gont
SI6 Networks
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