Re: [Lsr] FW: New Version Notification for draft-bonica-lsr-ip-flexalgo-00.txt

Hi Ron,

I can only guess the use-case, but it may be worth of documenting it in 
the draft.

Your proposal is basically mimicking SRv6 Locator behavior for regular 
IPv6 and IPv4 prefixes. One can even argue that for IPv6 you can use a 
Locator advertisement with no SIDs, but I agree that would be a hack and 
separate encoding is cleaner.

One thing that needs further work is the algo participation part. Given 
that we have a separate participation for SR and IP flex-algo, one would 
have to run a separate calculation each in the context of the same 
flex-algo. Even though in most cases one would expect the set of 
participating routers to be the same for both. I don't see an easy way 
out, actually this is what the base FA draft requires it in section 
10.2. What I would suggest is to clearly document the fact that the 
computation for the IP flex-algo is independent of the other flex-algo 
computations (e.g. SR) and that IP flex-algo is an application of its 
own from the flex-algo perspective.

Les has commented on ISIS encoding, I have a question on OSPF one - have 
you considered using the OSPFv2 Extended Prefix Opaque LSA with OSPFv2 
Extended Prefix TLV (rfc7684) and define a new "IP Felex-algo" metric 
sub-TLV?

thanks,
Peter

On 29/09/2020 15:37, Ron Bonica wrote:
> 
> Please review and comment
> 
>                                         Ron
> 
> 
> 
> Juniper Business Use Only
> 
>> -----Original Message-----
>> From: internet-drafts@ietf.org <internet-drafts@ietf.org>
>> Sent: Tuesday, September 29, 2020 9:36 AM
>> To: Parag Kaneriya <pkaneria@juniper.net>; Shraddha Hegde
>> <shraddha@juniper.net>; Ron Bonica <rbonica@juniper.net>; Rajesh M
>> <mrajesh@juniper.net>; William Britto A J <bwilliam@juniper.net>
>> Subject: New Version Notification for draft-bonica-lsr-ip-flexalgo-00.txt
>>
>> [External Email. Be cautious of content]
>>
>>
>> A new version of I-D, draft-bonica-lsr-ip-flexalgo-00.txt
>> has been successfully submitted by Ron Bonica and posted to the IETF
>> repository.
>>
>> Name:           draft-bonica-lsr-ip-flexalgo
>> Revision:       00
>> Title:          IGP Flexible Algorithms (Flexalgo) In IP Networks
>> Document date:  2020-09-29
>> Group:          Individual Submission
>> Pages:          14
>> URL:            https://urldefense.com/v3/__https://www.ietf.org/id/draft-bonica-
>> lsr-ip-flexalgo-00.txt__;!!NEt6yMaO-gk!X7PVDP-
>> FnUA0oCcZMw3Qde6in0C72hu_9hOZ53kPspIarR8fNDyU9Vck80Zbjoij$
>> Status:
>> https://urldefense.com/v3/__https://datatracker.ietf.org/doc/draft-bonica-lsr-
>> ip-flexalgo/__;!!NEt6yMaO-gk!X7PVDP-
>> FnUA0oCcZMw3Qde6in0C72hu_9hOZ53kPspIarR8fNDyU9Vck8x7e5ZqI$
>> Htmlized:
>> https://urldefense.com/v3/__https://datatracker.ietf.org/doc/html/draft-
>> bonica-lsr-ip-flexalgo__;!!NEt6yMaO-gk!X7PVDP-
>> FnUA0oCcZMw3Qde6in0C72hu_9hOZ53kPspIarR8fNDyU9Vck82w_6CyU$
>> Htmlized:       https://urldefense.com/v3/__https://tools.ietf.org/html/draft-
>> bonica-lsr-ip-flexalgo-00__;!!NEt6yMaO-gk!X7PVDP-
>> FnUA0oCcZMw3Qde6in0C72hu_9hOZ53kPspIarR8fNDyU9Vck81_QrJ_p$
>>
>>
>> Abstract:
>>     An IGP Flexible Algorithm computes a constraint-based path and maps
>>     that path to an identifier.  As currently defined, Flexalgo can only
>>     map the paths that it computes to Segment Routing (SR) identifiers.
>>     Therefore, Flexalgo cannot be deployed in the absence of SR.
>>
>>     This document extends Flexalgo, so that it can map the paths that it
>>     computes to IP addresses.  This allows Flexalgo to be deployed in any
>>     IP network, even in the absence of SR.
>>
>>
>>
>>
>> Please note that it may take a couple of minutes from the time of submission
>> until the htmlized version and diff are available at tools.ietf.org.
>>
>> The IETF Secretariat
>>
> _______________________________________________
> Lsr mailing list
> Lsr@ietf.org
> https://www.ietf.org/mailman/listinfo/lsr
> 
> 