42nd IETF OSPF WG Meeting Notes Rob Coltun opened the meeting with an introduction and summary of new RFC and draft revisions since the LA IETF. These include: 1. RFC 2370 - Opaque LSA Option 2. John Moy's revised MOSPF Draft 3. New Version of NSSA Draft (Updates RFC 1587) Rob then went through the differences between the new MOSPF draft and RFC 1584. These differences can be classified as one of 4 types: 1. Bug fixes to the current specification. 2. Changes for consistency with RFC 2328. 3. Changes in support of IGMPv2. 4. Clarifications in response to questions on RFC 1584. Rob expects there to be at least one more revision of the draft but those wishing to review the draft should not delay. The draft is draft-ietf-mospf-mospf-00.txt. Cyndi Jung from 3Com presented the results of the MOSPF Inter-Op IPMI testing performed in June. Interoperability of 4 MOSPF implementations was tested. These included Bay, Ascend/Cascade, 3Com and IBM. Mixed MOSPF and DVMRP dmains tested successfully. Inter-area test with a DVMRP domain and non-MOSPF OSPF area caused confusion due to the fact that the RPF preferred the non-multicast inter-area route to the multicast capable external route (via the DVMRP domain). However, this is consisent with the specification. Next Rob indicated that an Internet Draft was in the works based on Daniel Awduche's requirements for MPLS traffic engineering. Expect this to be discussed at the next IETF. Finally, Pat Murphy from the US Geological Survey/Department of Interior presented the 2 drafts he has been working on. The first was the latest OSPF NSSA option revision (draft-ietf-ospf-nssa-update-05.txt). The main differences between the new draft and RFC 1587 include: 1. Type 3 Summary LSAs can be inhibited from being advertised into NSSA's. Rather, a single default (0/0) type 3 LSA is advertised by the ABR(s). 2. There is configuration control over which ABR(s) translate 7 type NSSA LSA's to type 5 LSA. An ABR can be configured to always translate type 7 LSA's, never translate type 7 LSA's or participate in the election process. Pat presented problems with installing routes corresponding to NSSA type 7 LSAs with their P-bit clear. The concensus was to leave the base NSSA draft as it is and document the problems in an appendix. Pat favors policy based filtering so that packets originating within an NSSA could still use routes corresponding these P-bit clear type 7 LSAs. While this is the most flexible, there was general agreement that this should not be a requirement for OSPF NSSA implementation. Pat also drew a picture of his overall OSPF area architecture and discussed the size and complexity of the multi-agency OSPF network for which he is responsible. Pat will issue a new draft in the near term and Rob/John will request last call. Last, Pat presented his proposal for multiple area links. This is to satisfy the requirement to use an inter-area path including a high speed backbone link rather than the intra-area path. The proposal introduces the concept of secondary adjacencies in the non-backbone areas and utilizes Opaque LSAs to augment the intra-area area route computation process. Pedro Marques (Cisco), Tony Przygienda (Lucent), and Acee Lindem (IBM) all indicated that there should be a simpler solution to this problem. Pedro suggested using an IP tunnel across the backbone for each non-backbone area. Acee suggested simply allowing the backbone area interface to be configured in multiple areas. It would be represented as an unnumbered link in non-backbone areas. Acee will post an E-mail to the OSPF list elaborating on this proposal. Others are encouraged to submit their ideas for solving this problem.