P. Psenak, S.Previdi, C. Filsfils – Cisco W. Henderickx – Nokia draft-ietf-ospf-segment-routing-extensions-10 draft-ietf-ospf-ospfv3-segment-routing-extensions-07 P. Psenak, S.Previdi, C. Filsfils – Cisco W. Henderickx – Nokia Jeff Tantsura H. Gredler, RtBrick R. Shakir, Jive Communications

OSPF SR Drafts Evolution Originally posted in June 2013 – IETF 87 Drafts went through several rounds of updates Presented in IETF 88, IETF 90, IETF91, IETF93, IETF94, IETF95, IETF96, IETF97. OSPFv2/v3 SR drafts are kept in sync

Changes since last IETF Handling of multiple SR-Algorithm sub-TLVs on receiver side has been clarified in section 3.1 Similar rules are used for other SR capability sub-TLVs SR Local Block Sub-TLV SRMS Preference Sub-TLV

Changes since last IETF (cont.) SR Local Block Sub-TLV was introduced in section 3.3. Contains the range of labels the node has reserved for local SIDs. Adjacency-SIDs, Binding-SIDs, etc.

Changes since last IETF (cont.) SRMS Preference Sub-TLV was introduced in section 3.4. Used to advertise a preference associated with the node that acts as a SR Mapping Server Usage described in draft-ietf-spring-conflict-resolution

Changes since last IETF (cont.) Text has been added to clarify the handling of the Algorithm in the Prefix-SID: “A router receiving a Prefix-SID from a remote node and with an algorithm value that such remote node has not advertised in the SR-Algorithm sub-TLV (Section 3.1) MUST ignore the Prefix-SID sub- TLV.”

Changes since last IETF (cont.) Below text has been removed from the draft. SID preference rules are now described in draft-ietf-spring-conflict-resolution “If the Prefix-SID that is advertised in a Prefix SID Sub-TLV is also covered by the OSPF Extended Prefix Range TLV, the Prefix-SID advertised in Prefix SID Sub-TLV MUST be preferred.”

Next Steps Socialize draft changes at IETF 97 Discuss changes on mailing list Gauge readiness for WGLC