Hi Andrew,

I understand your point and thanks for your suggestion.

I've just posted an update that reflects this change:
https://datatracker.ietf.org/doc/html/draft-ietf-lsr-ospfv3-srv6-extensions-14

Thanks,
Ketan


On Thu, Jun 8, 2023 at 4:30 PM Andrew Alston - IETF <[email protected]>
wrote:

> Hi Ketan,
>
>
>
> Thanks for the clarification and apologies for the misunderstanding.
>
>
>
> What I would suggest is that a line be added to section 9 to make it
> explicitly clear that the end.x TLV’s are NOT sub-tlv’s of the locator –
> because while I realize on a second read that this is stated – it’s very
> easy to miss and I think this could end up with implementors making a
> similar mistake in the reading that I did.
>
>
>
> Thanks
>
>
>
> Andrew
>
>
>
>
>
> *From: *Ketan Talaulikar <[email protected]>
> *Date: *Thursday, 8 June 2023 at 13:16
> *To: *Andrew Alston - IETF <[email protected]>
> *Cc: *The IESG <[email protected]>,
> [email protected] <
> [email protected]>, [email protected] <
> [email protected]>, [email protected] <[email protected]>, [email protected] <
> [email protected]>
> *Subject: *Re: Andrew Alston's Discuss on
> draft-ietf-lsr-ospfv3-srv6-extensions-13: (with DISCUSS)
>
> CAUTION: This email has originated from a free email service commonly used
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>
>
> Hi Andrew,
>
>
>
> Thanks for your review and please check inline below for responses.
>
>
>
>
>
> On Thu, Jun 8, 2023 at 2:50 PM Andrew Alston via Datatracker <
> [email protected]> wrote:
>
> Andrew Alston has entered the following ballot position for
> draft-ietf-lsr-ospfv3-srv6-extensions-13: Discuss
>
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>
>
>
> ----------------------------------------------------------------------
> DISCUSS:
> ----------------------------------------------------------------------
>
> Hi There,
>
> Firstly thanks for the document.
>
> I'd like to have a discussion about the following text in Section 7.1.
>
> If the SRv6 Locator TLV for
>    the same Locator appears in multiple SRv6 Locator LSAs that have the
>    same flooding scope, the TLV in the SRv6 Locator LSA with the
>    numerically smallest Link-State ID MUST be used and subsequent
>    instances of the TLV MUST be ignored.
>
> My question may be as a result of not quite understanding the nature of
> End.X
> SID's - and as such, this may be easy to resolve.  But - Reading the
> document,
> you have a limit of the size of an OSPFv3 packet of 65535 bytes (with
> fragmentation - which I would argue you probably don't wanna rely on).
> Now, if
> you are stacking END.X sub-TLV's beneath a locator SID - and you require
> more
>
>
>
> KT> The End.X sub-TLVs are not advertised under the Locator TLV but as
> sub-TLVs of each link/adjacency under the E-Router-Link TLV - refer
> https://datatracker.ietf.org/doc/html/draft-ietf-lsr-ospfv3-srv6-extensions-13#section-9.
> Furthermore, the E-Router-LSA that carry the E-Router-Link TLV can have
> multiple instances to accomodate a large set of links - most granularly it
> could be one E-Router-LSA carrying a single link/adjacency each. This flows
> from the base OSPFv3 spec - refer
> https://datatracker.ietf.org/doc/html/rfc5340#section-4.4.3.2.
>
>
>
> than 4000 of them on a large device (though in reality its probably far
> less
> than this because of overhead etc - if you avoid fragmentation even on a
> large
> MTU network you're at under 500) you're going to run into a problem
> because you
> cannot split the announcement by using the same locator in subsequent
> LSA's (my
> understanding is that normally this would be accomplished by having the
> same
> locator in multiple LSA's with different LS ID's, that the router would
> then
> combine).
>
> So - the question is - under what scenarios are END.X and END sub tlv's
> added
> to the packet and advertised - and could we run into a major length problem
> here on large dense devices that are, for example, terminating huge
> numbers of
> cross connects.  Further to this, is there a reason why the locator cannot
> be
> split across multiple packets with different Link State ID's to reduce the
> size
> of the OSPF packets if this does become necessary?
>
>
>
> KT> As explained above, a large number of links would not result in growth
> of the SRv6 Locator TLV size. Since the SRv6 Locator is like an object on
> the same lines as a Link or a Prefix in OSPFv3, if it were to grow large
> the protocol mechanism today allows it to grow to the largest IP packet
> size of 64K (and subject to IP fragmentation). The OSPFv3 level
> fragmentation is available at an object level - i.e. different LSAs for
> each individual link or prefix or locator object is possible. If we ever
> get to a situation where we need to extend this protocol fragmentation
> capability, we would need to come up with a generic OSPFv3 mechanism to
> break a single object into multiple parts for all types of objects - not
> just the SRv6 Locator. IMHO, we don't yet have a case to do so.
>
>
>
> Thanks,
>
> Ketan
>
>
>
>
> (I do realise that you could use multiple locators on the same router to
> split
> this up - but would argue thats going to create operational nightmares and
> lead
> to potentially big problems with admins having to figure out when they are
> going to hit the limit)
>
>
>
>
>
> Internal All Employees
>
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