Re: [Lsr] Second Working Last Call for draft-ietf-lsr-flex-algo

[Peter Psenak <[e-mail]>]

Hi Bruno,

On 17/06/2021 16:12, [e-mail] wrote:
> Hi,
> 
> I have a question/comment.
> 
> I think that we all agree that FlexAlgo/Link State computation requires 
> that all node use the same topology to compute their SPF. Otherwise, 
> permanent forwarding loops are probable.
> 
> https://datatracker.ietf.org/doc/html/draft-ietf-lsr-flex-algo-16#section-12 
> says
> 
> “ASLA Admin Group Advertisements to be used by the Flexible Algorithm
> 
> Application MAY use either the Administrative Group or Extended
> 
> Administrative Group encodings. »
> 
> My reading of the above is that the sender of the attribute is free to 
> advertise either Administrative Groups or Extended Administrative Group 
> encoding (or both).

correct.

> 
> In order to enforce topology consistency, I’m assuming that there is a 
> non-expressed requirement for the node reading the attribute to be able 
> to read both. (ie. MUST support the reading of both encodings).

yes, the receiver MUST be able to accept both.


> 
> Is this a correct assumption?
> 
> - if so, could this requirement be written in the document. (If we have 
> to choose one, I’d rather have the “MUST” requirement expressed rather 
> than the “MAY”)

will add to the text.

thanks,
Peter


> 
> - if not, how is the topology made consistent across all nodes?
> 
> Thank you,
> 
> Regards,
> 
> --Bruno
> 
> *From**:*Lsr [mailto:[e-mail]] *On Behalf Of *Acee Lindem (acee)
> *Sent:* Wednesday, June 16, 2021 4:01 PM
> *To:* [e-mail]
> *Cc:* [e-mail]; Christian Hopps <[e-mail]>; 
> [e-mail]
> *Subject:* [Lsr] Second Working Last Call for draft-ietf-lsr-flex-algo
> 
> After the first successful WG last call, the authors discovered that 
> some re-work was needed for OSPF AS External route calculation – 
> specifically with respect to the Flex Algorithm ASBR metrics and 
> calculation. This was fixed and there were clarifications in the IANA 
> section (see versions -14 and -15). The draft has been stable since 
> April and we are now ready to WG last call the updated version.
> 
> Without further ado, this begins a 2 week WG Last Call, ending on July 
> 1st, 2021, for draft-ietf-lsr-flex-algo
> 
> https://datatracker.ietf.org/doc/draft-ietf-lsr-flex-algo/
> 
> All authors, please indicate by sending an email to the list, whether 
> you aware of any other IPR beyond what is already posted:
> 
>    [>From 
> https://datatracker.ietf.org/ipr/search/?submit=draft&id=draft-ietf-lsr-flex-algo]
> 
> https://datatracker.ietf.org/ipr/3910/
> 
> https://datatracker.ietf.org/ipr/3248/
> 
> Thanks,
> 
> Chris & Acee.
> 
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