Hi Shraddha, When the ABR originates the Extended Prefix TLV with A (attached) bit set, it indicates that the prefix belongs to it (i.e. connected in perhaps another area on the same node). So PHP must be done on previous router.
I don't see the issue or need for clarification here. Or am I not following your point well? Thanks, Ketan -----Original Message----- From: OSPF [mailto:ospf-boun...@ietf.org] On Behalf Of Shraddha Hegde Sent: 10 May 2017 11:05 To: internet-dra...@ietf.org; i-d-annou...@ietf.org Cc: ospf@ietf.org Subject: Re: [OSPF] I-D Action: draft-ietf-ospf-segment-routing-extensions-13.txt Authors, Apologies for being late with this comment in the process of standardization. The below section 5 describes the PHP for mapping server " As the Mapping Server does not specify the originator of a prefix advertisement, it is not possible to determine PHP behavior solely based on the Mapping Server advertisement. However, PHP behavior SHOULD be done in following cases: The Prefix is intra-area type and the downstream neighbor is the originator of the prefix. The Prefix is inter-area type and downstream neighbor is an ABR, which is advertising prefix reachability and is also generating the Extended Prefix TLV with the A-flag set for this prefix as described in section 2.1 of [RFC7684]." The text says "PHP behavior" should be done in following cases. In the second case here it's an ABR re-advertising a prefix and SID being advertised for this Prefix from a mapping server. If we interpret "PHP behavior should be done" As the penultimate router removing the label and forwarding the packet to ABR, It does not work since the inner labels gets exposed at the ABR. Request authors to add clarification text around "PHP behavior". Rgds Shraddha -----Original Message----- From: OSPF [mailto:ospf-boun...@ietf.org] On Behalf Of internet-dra...@ietf.org Sent: Thursday, May 4, 2017 3:28 PM To: i-d-annou...@ietf.org Cc: ospf@ietf.org Subject: [OSPF] I-D Action: draft-ietf-ospf-segment-routing-extensions-13.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 Extensions for Segment Routing Authors : Peter Psenak Stefano Previdi Clarence Filsfils Hannes Gredler Rob Shakir Wim Henderickx Jeff Tantsura Filename : draft-ietf-ospf-segment-routing-extensions-13.txt Pages : 35 Date : 2017-05-04 Abstract: Segment Routing (SR) allows a flexible definition of end-to-end paths within IGP topologies by encoding paths as sequences of topological sub-paths, called "segments". These segments are advertised by the link-state routing protocols (IS-IS and OSPF). This draft describes the OSPF extensions required for Segment Routing. The IETF datatracker status page for this draft is: https://datatracker.ietf.org/doc/draft-ietf-ospf-segment-routing-extensions/ There are also htmlized versions available at: https://tools.ietf.org/html/draft-ietf-ospf-segment-routing-extensions-13 https://datatracker.ietf.org/doc/html/draft-ietf-ospf-segment-routing-extensions-13 A diff from the previous version is available at: https://www.ietf.org/rfcdiff?url2=draft-ietf-ospf-segment-routing-extensions-13 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
