Update to The OSPF Opaque LSA Option draftbergerospfrfc

Update to: The OSPF Opaque LSA Option draft-berger-ospf-rfc 2370 bis Lou Berger (lberger@labn. net) Igor Bryskin (ibryskin@advaoptical. com) Alex Zinin (zinin@psg. com) Original Author: Rob Coltun

Draft Background • There is no way for OSPF routers to validate OSPF AS-scope (type 11) Opaque LSAs received outside of the LSA originator’s area – Issue presented / addressed in draft-bryskin-ospf-lsa-type 11 -validation • Presented at last IETF OSPF WG • Conclusion from last WG meeting: Rev RFC 2370 IETF-67

Changes In Draft From RFC 2370 • Updated draft format • Adopted RFC 2119 terminology – Key words "MUST", "MUST NOT", "REQUIRED", … – Requires WG review – no issues expected • Added “Routers processing opaque LSAs MAY choose to give priority to processing base OSPF LSA types over opaque LSA types. ” • Added reference to draft-ietf-ospf-mib-update • Added Inter-Area Considerations – From draft-bryskin-ospf-lsa-type 11 -validation • Removed reference to expired drafts IETF-67

Inter-Area Solution As presented at last IETF: • Parallels and reuses the mechanism for validation of OSPF type 5 LSAs • Validation of type-5 LSAs – AS external route (type-5) LSAs have also the ASscope, hence there is a similar problem with their validation – The problem is addressed via use of area-scope ASBR-summary (type-4) LSAs originated by ABRs for every known ASBR – The validation of AS-scope (type-11) opaque LSAs could be achieved if ABRs treat their originators as ASBRs IETF-67

Inter-Area Solution (cont) • LSA origination changes – Routers that originate AS-scope opaque LSAs also set the E-bit in the Options field of originated OSPF Hello packets – Such Routers also set the E-bit in the Options field of the header of each LSA it injects into the network • LSA validation changes – Router MUST look up the routing table for the ASBR with the Router ID matching the Advertising Router ID found in the received LSA header. – If no entries could be found (i. e. , ASBR is unreachable), the router ignores the LSA. – A router MUST discontinue using ALL Opaque LSAs originated by a router that is identified as being unreachable IETF-67

Next Steps • WG Feedback – Review of RFC 2119 terminology – Any other changes needed? • • Adoption as WG document IETF-67

Thank You