Hi Tom,
Thanks a lot for your comments!
There're two types of header limits mentioned in draft-ietf-6man-eh-limits
section 2.2.6.
One is the size limit for the IPv6 header chain, and another is the whole
header chain size limit(or Aggregate Header Limit as in RFC8883).
I think our requirement is similar with Aggregate Header Limit.
While there're some description about Aggregate Header Limit in RFC8883, such
as:
"If the aggregate length of headers in a packet exceeds the size of the parsing
buffer, a device will either discard the packet or defer processing to a
software slow path." "a node that is unable to process the headers of a
packet due to the aggregate size of the packet headers exceeding a processing
limit."
there seem no explicit definition about it.
Do you think a more explicit description is required, such as, "Aggregate
Header Limit is the total header size(in IPv6, it comprise the IPv6 header
chain as well as any headers that are part of network encapsulation that
precedes the innermost transport layer) that a router is able to process at
full forwarding rate, for some device, this limit is related with its buffer
size".
While sending ICMPv6 for nodes' header size limit detecting and collecting is a
solution, in an SR domain, there may be many nodes(either as headend or
intermediate nodes) able to increase the total header size, and the SR path can
be dynamic. So it's not easy for these node to obtain the Aggregate Header
Limits of the downstream nodes by sending and processing the ICMP messages.
There would be many ICMP messages produced and it's a burden for the nodes in a
large domain.
So signaling this limit is proposed as a solution in our draft.
Another question of mine is, for a router with certain buffer size, aren't the
IPv6 header chain limit size and the whole header chain limit of the same value?
Thanks,
Yao
Original
From: TomHerbert <t...@herbertland.com>
To: 刘尧00165286;
Cc: i...@ietf.org <i...@ietf.org>;spring@ietf.org <spring@ietf.org>;
Date: 2023年10月20日 01:03
Subject: Re: [IPv6] Fw: New Version Notification for
draft-liu-6man-max-header-size-00.txt
Please look at draft-ietf-6man-eh-limits that is.
Tom
On Thu, Oct 19, 2023 at 10:02 AM Tom Herbert <t...@herbertland.com> wrote:
>
> Yao,
>
> Please look at draft-herbert-6man-eh-limits and RFC8883. The draft
> defines limits for things like maximum IPv6 header chain and maximum
> extension header size. The RFC defines ICMP errors that can be sent if
> a limit is exceeded.
>
> These can be applied to easily discover what the maximum IPv6 header
> length is in a limited domain (like segment routing domain). A host
> would send packets with extension headers, could be probes, to a
> destination. If routers in the path can't handle the size of the IPv6
> header they can drop the packet and send an ICMP error per RFC8883.
>
> Tom
>
>
> On Thu, Oct 19, 2023 at 9:06 AM <liu.ya...@zte.com.cn> wrote:
> >
> > Dear All，
> >
> > We've submitted a new draft
> > https://www.ietf.org/archive/id/draft-liu-6man-max-header-size-00.html.
> >
> > This document proposes the concept and the requirement of IPv6 Maximum
> > Header Size to represent the total header size(IPv6 header and IPv6
> > extension headers) that a node is able to process from an incoming packet
> > in IPv6, as well as the signaling requirement for it.
> >
> >
> > Welcome your review and comments！
> >
> >
> > Regards,
> >
> > Yao
> >
> > Original
> > From: internet-dra...@ietf.org <internet-dra...@ietf.org>
> > Date: 2023年10月19日 23:59
> > Subject: New Version Notification for draft-liu-6man-max-header-size-00..txt
> > A new version of Internet-Draft draft-liu-6man-max-header-size-00.txt has
> > been
> > successfully submitted by Yao Liu and posted to the
> > IETF repository.
> >
> > Name: draft-liu-6man-max-header-size
> > Revision: 00
> > Title: IPv6 Maximum Header Size Requirement
> > Date: 2023-10-19
> > Group: Individual Submission
> > Pages: 6
> > URL:
> > https://www.ietf.org/archive/id/draft-liu-6man-max-header-size-00.txt
> > Status: https://datatracker.ietf.org/doc/draft-liu-6man-max-header-size/
> > HTML:
> > https://www.ietf.org/archive/id/draft-liu-6man-max-header-size-00.html
> > HTMLized:
> > https://datatracker.ietf.org/doc/html/draft-liu-6man-max-header-size
> >
> >
> > Abstract:
> >
> > This document proposes the concept and the requirement of IPv6
> > Maximum Header Size to represent the total header size that a node is
> > able to process from an incoming packet in IPv6, as well as the
> > requirement for it.
> >
> >
> >
> > The IETF Secretariat
> >
> >
> > --------------------------------------------------------------------
> > IETF IPv6 working group mailing list
> > i...@ietf.org
> > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6
> > --------------------------------------------------------------------
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