All, Link-local flooding was added as an optimization for use-cases that do not need area level flooding on request from Acee. I agree flooding area level in all cases is a reasonable way forward as the overhead isn't much.
If anyone has objections to removing Link-local scope advertisement, do let me know. Rgds Shraddha -----Original Message----- From: Acee Lindem (acee) [mailto:a...@cisco.com] Sent: Thursday, July 6, 2017 2:55 PM To: Peter Psenak (ppsenak) <ppse...@cisco.com>; Ketan Talaulikar (ketant) <ket...@cisco.com>; Shraddha Hegde <shrad...@juniper.net> Cc: ospf@ietf.org Subject: Re: [OSPF] I-D Action: draft-ietf-ospf-link-overload-07.txt Hi Peter, Shradha, On 7/6/17, 3:30 AM, "OSPF on behalf of Peter Psenak (ppsenak)" <ospf-boun...@ietf.org on behalf of ppse...@cisco.com> wrote: >On 06/07/17 05:50 , Ketan Talaulikar (ketant) wrote: >> Hi Shraddha, >> >> Thanks for taking care of some of the comments shared previously. >>Please find below some more that were probably missed or not taken >>care of. >> >> 1) I see that the use of link-local scope RI LSA has still been >>retained in this version and not sure why. RI LSA is for node >>attributes and it's use for signalling of link is not right IMO. Why >>not use the link-local scope Extended Link LSA instead? > >an alternative would be to always flood area scope Extended Link LSA. >It should not harm anything and could be used by other routers in area >as a "heads-up" that remote link is becoming overloaded. I think this would be a good way forward as the OSPF Extended Attribute LSA will most likely be advertised for SR in OSPF Service Provider domains anyway. So, just advertising the area-scope for all use cases would seem to be the simplify this approach and get us past this discussion. In fact, the -00 version of the draft had area-scope alone and I, regretfully, had suggested the OSPF RI as possible way to get support either scope. Thanks, Acee > > >> >> 2) Sec 5.1, why is advertising of MAX-METRIC for the link to be >>overloaded a SHOULD and not a MUST? Isn't this mandatory to ensure >>backward compatibility? What if the router on which overload is >>signalled does not do MAX-METRIC but the implementation on the remote >>side end up doing MAX-METRIC. Would it not result in asymmetric metric >>in a un-intended manner? Please consider changing all SHOULD here to >>MUST to ensure backward compatibility. >> >> 3) Sec 5.4, can you please make similar change in language related to >>the RFC4203 reference as you've done in other parts in this version? >> >> Also I don't agree with the rationale you've given for not using LLS >>for the link-local signalling. Even if the hello processing were >>delegated to the LC, there are already a lot of protocol events which >>can happen via hello packets (which includes LLS) that require >>signalling update to the control plane OSPF main process. An >>implementation aspect such as this should hardly be a good reason to >>not use LLS for link-local signalling such as overload. > >+1 on the above. > >thanks, >Peter > >> >> Thanks, >> Ketan >> >> -----Original Message----- >> From: OSPF [mailto:ospf-boun...@ietf.org] On Behalf Of Shraddha Hegde >> Sent: 03 July 2017 11:11 >> To: internet-dra...@ietf.org; i-d-annou...@ietf.org >> Cc: ospf@ietf.org >> Subject: Re: [OSPF] I-D Action: draft-ietf-ospf-link-overload-07.txt >> >> OSPF WG, >> >> New version of the ospf-link-overload draft is posted. >> Editorial comments received so far have been addressed in this version. >> >> There was one comments to move the link-overload sub-TLV to LLS in >>hello messages. >> Many implementations delegate the Hello processing to >>linecards/different deamons Once adjacency is established. Hello >>messages are not sent to control plane post adjacency establishment. >>The link-overload information typically needs to be processed after >>adjacency establishment, it introduces unnecessary complexity in hello >>processing. >> We had a discussion among authors on this and feel advertising >>link-overload sub-TLV in the LSAs is the most appropriate mechanism. >> >> >> >> Rgds >> Shraddha >> >> -----Original Message----- >> From: OSPF [mailto:ospf-boun...@ietf.org] On Behalf Of >>internet-dra...@ietf.org >> Sent: Monday, July 3, 2017 11:01 AM >> To: i-d-annou...@ietf.org >> Cc: ospf@ietf.org >> Subject: [OSPF] I-D Action: draft-ietf-ospf-link-overload-07.txt >> >> >> A New Internet-Draft is available from the on-line Internet-Drafts >>directories. >> This draft is a work item of the Open Shortest Path First IGP of the >>IETF. >> >> Title : OSPF Link Overload >> Authors : Shraddha Hegde >> Pushpasis Sarkar >> Hannes Gredler >> Mohan Nanduri >> Luay Jalil >> Filename : draft-ietf-ospf-link-overload-07.txt >> Pages : 14 >> Date : 2017-07-02 >> >> Abstract: >> When a link is being prepared to be taken out of service, the >>traffic >> needs to be diverted from both ends of the link. Increasing the >> metric to the highest metric on one side of the link is not >> sufficient to divert the traffic flowing in the other direction. >> >> It is useful for routers in an OSPFv2 or OSPFv3 routing domain to be >> able to advertise a link being in an overload state to indicate >> impending maintenance activity on the link. This information can be >> used by the network devices to re-route the traffic effectively. >> >> This document describes the protocol extensions to disseminate link- >> overload information in OSPFv2 and OSPFv3. >> >> >> >> The IETF datatracker status page for this draft is: >> https://datatracker.ietf.org/doc/draft-ietf-ospf-link-overload/ >> >> There are also htmlized versions available at: >> https://tools.ietf.org/html/draft-ietf-ospf-link-overload-07 >> https://datatracker.ietf.org/doc/html/draft-ietf-ospf-link-overload-0 >> 7 >> >> A diff from the previous version is available at: >> https://www.ietf.org/rfcdiff?url2=draft-ietf-ospf-link-overload-07 >> >> >> 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. >> >> Internet-Drafts are also available by anonymous FTP at: >> ftp://ftp.ietf.org/internet-drafts/ >> >> _______________________________________________ >> OSPF mailing list >> OSPF@ietf.org >> https://www.ietf.org/mailman/listinfo/ospf >> >> _______________________________________________ >> OSPF mailing list >> OSPF@ietf.org >> https://www.ietf.org/mailman/listinfo/ospf >> >> _______________________________________________ >> OSPF mailing list >> OSPF@ietf.org >> https://www.ietf.org/mailman/listinfo/ospf >> . >> > >_______________________________________________ >OSPF mailing list >OSPF@ietf.org >https://www.ietf.org/mailman/listinfo/ospf _______________________________________________ OSPF mailing list OSPF@ietf.org https://www.ietf.org/mailman/listinfo/ospf
