which router advertises multiple Prefix-SIDs for the same prefix in your example? -> ABRs (RT1 and RT2) advertise resolved SID(i.e. SID:1) in area a1 for same prefix 10.10.10.10.
Now on configuration change at RT1 (i.e. SID:4), RT1 assumes SID:1 be originated by RT2 and runs conflict resolution -> Regards, Mahendra -----Original Message----- From: Peter Psenak [mailto:ppse...@cisco.com] Sent: 23 February 2018 13:59 To: Mahendra Singh Negi; draft-ietf-spring-conflict-resolut...@ietf.org; draft-ietf-ospf-segment-routing-extensi...@ietf.org Cc: ospf@ietf.org Subject: Re: draft-ietf-spring-conflict-resolution/draft-ietf-ospf-segment-routing-extensions: If you please provide your inputs on the issue. Mahendra, On 23/02/18 05:48 , Mahendra Singh Negi wrote: > Dear Authors, > > Amidst implementing conflict resolution for OSPF SR ( > https://tools.ietf.org/html/draft-ietf-spring-conflict-resolution-05) > we came across this issue. > > ** > > ** > > *Topology:* > > *Issue:* > > 1.Prefix conflict occurs at RT1 and RT2. > > 2.Both RT1 and RT2 resolve the conflict and download corresponding > Label for SID:1 (SID:1 wins conflict resolution). > > 3.Both RT1 and RT2 advertise inter-area Extended Prefix Opaque LSA for > prefix 10.10.10.10 in area a1 with SID:1. > > Reference: > https://tools.ietf.org/html/draft-ietf-ospf-segment-routing-extensions > -24#section-7.2 > > > & > > https://tools.ietf.org/html/draft-ietf-ospf-segment-routing-extensions > -24#section-5 > > > (If an OSPF router advertises multiple Prefix-SIDs for the same > prefix, topology and algorithm, all of them MUST be ignored.) which router advertises multiple Prefix-SIDs for the same prefix in your example? > > 4.Now at RT1, user *changes the SID configuration value to 4*, and > still SID 1 wins the conflict resolution as in area a1 RT2 has not > flushed or updated SID:1, and SID:1 is forever in LSDB. I don't understand the above. Why would that happen? Peter > > *How to fix the issue?* > > a)think ABRs should advertise all the SIDs to leaking areas and MUST > condition mentioned highlighted in yellow above be relaxed(i.e. update > inter-area segment routing section accordingly) and let each node run > conflict-resolution. > > b) On SID configuration change, RT1 Flushes the SID:1 and waits for > SID:1 flushing out from the LSDB and then originates with new > SID:4.(How long to wait is decided locally). > > I prefer (a), if you please provide your opinion on this.We are under > development, highly appreciate prompt responses. > > Regards, > > Mahendra > _______________________________________________ OSPF mailing list OSPF@ietf.org https://www.ietf.org/mailman/listinfo/ospf
