CURRENT_MEETING_REPORT_ Reported by Ross Callon/DEC IS-IS Minutes The IS-IS Working Group met at the IETF meeting in Atlanta, Georgia. There were two topics of discussion: A brief overview of the status of the IS-IS spec (led by Ross Callon), and a presentation and longer discussion of the SNMP MIB for IS-IS (led by Chris Gunner). 1. Status of IS-IS Ross reported that the OSI IS-IS Intra-Domain routing protocol (ISO DIS 10589) has completed the Draft International Standard (DIS) ballot, and all ballot comments were successfully resolved at a recent ISO meeting. This implies that the ISO IS-IS will be progressing to final International Standard state relatively quickly. This, in combination with the completion of a couple of Integrated IS-IS implementations means that it is a good time to start think about issuing an update to RFC 1195. Ross then gave a quck overview of some minor changes that would be involved: o Reference to ISO standard RFC 1195 reference the DP version of ISO IS-IS. This clearly needs to be updated to reference the final International Standard version, when available. This would also imply that Annex B (Encoding of Sequence Number Packets) can be removed. It turns out that we were either lucky or good, and the sequence number format in the current ISO document is compatible with Annex B. o RIP (or other external routes) at level 1 Currently the spec says that this is not allowed. There are good technical reasons why we don't want fully general external connections at both level 1 and level 2. However, there may be many cases where we have a small RIP ``island'' which is only reachable via a level 1 area. For example, this is very likely to occur during transition from a RIP routing domain to an Integrated IS-IS routing domain. No technical change is needed, but the document should be upgraded editorially to specify that this is permissible. o Default IP route at level 1. There will be some cases where level 1 routing is IP-capable (using Integrated IS-IS) but level 2 routing is not (such as using OSI-only IS-IS at level 2, or possibly during phase 4 to phase 5 DECnet(TM) transition). In this case, there needs to be a way for level 1 routers to know where to send traffic 1 destined to outside of the area (for example, one single level 2 router might be running RIP with external routers). The solution to this is to allow IP Default Route (subnet mask of all 0's) at level 1, and to specify that for level 1 only routers which see the default route advertised in level 1 LSPs, this takes precedence over forwarding traffic to level 2 routers. o Compatibility with earlier versions of IS-IS There should be a ``for information only'' annex which specifies the differences between RFC 1195, and the updated RFC. This will also specify how to ensure interoperability between old and new routers. o IS-IS / BGP interaction Yakov Rekhter brought up the issue of interaction between IS-IS and BGP. Ross and Yakov will work on this issue off-line, and report results back to the Working Group. o Encoding of Authentication Field Someone brought up the issue that RFC 1195 and DIS 10589 both have an authentication field, in which the encoding and use is identical but the code value is different. The Working Group agreed that this was an unnecessary redundancy, and that we should use the value from 10589. o Ships in the Night Operation RFC 1195 currently has sufficient functionality to allow operating two instances of IS-IS in ``Ships in the Night'' mode -- one instance would be for IP-only routing, and one for OSI-only routing. However, just how to do this is not written down anywhere. It was agreed that this should be writted down, with the approach ``you don't have to be capable to run two instances of IS-IS, but if you do run two instances then this is how you do it''. Generally, you demultiplex on the ``Protocols Supported'' field, and optionally may use authentication to protect against accidental merging of the two logical routing domains by a mis-configured router. 2. MIB for IS-IS Chris Gunner then gave a detailed presentation of the proposed MIB for IS-IS. This MIB allows management of Integrated IS-IS (including full management of both ISO 10589 and RFC 1195) using SNMP. This is based on the GDMO (i.e., ISO format network management information) contained in DIS 10589, with additional objects added for management of RFC 1195. The recent progression of 10589 in ISO will result in some changes to the GDMO in 10589. Chris will need to produce an update of the MIB in order to maintain alignment with the ISO document. 2 There was a discussion of the size of the MIB. In particular, there are situations where several similar things are in different tables For example, different sorts of circuits currently are managed using different tables. There is substantial overlap between these different tables. The alternative is to have one type of table for all circuits, with some fields not always used. This implies slightly more bits will be transmitted on the wire, but allows a smaller MIB and less software code (e.g., data structures are simpler). The Working Group agreed that the latter approach was preferable, at least in those cases where the overlap is relatively large. The group agreed that the MIB should permit multiple instances of Integrated IS-IS and/or IS-IS to be managed in a system. This means turning single instance objects in groups into table objects. The group also agreed that all such table entries should be capable of creation and deletion to mirror the creation and deletion capabilities of the DIS 10589 managed objects to which they are equivalent. 3. Other Issues Yakov Rekhter pointed out that the ISO GDMO of IS-IS does not allow measurement of routes coming from external protocols to IS-IS. Chris and Ross agreed to bring up this issue with the folks working on the ISO specification. Outside of the Working Group, a couple of folks brought up the issue of how to handle the ``3rd party router'' case (a single routing domain having several routers on a broadcase or general-topology network with only one router running BGP). Ross will write up a proposal on how to deal with this and discuss it within the Working Group. Attendees Nagaraj Arunkumar nak@3com.com William Barns barns@gateway.mitre.org Scott Barvick sbarvick@wellfleet.com William Biagi bbiagi@cos.com John Burruss jburruss@wellfleet.com Ross Callon callon@bigfut.enet.dec.com Dino Farinacci dino@cisco.com Dennis Ferguson dennis@canet.ca Robert Griffioen Chris Gunner gunner@osicwg.enet.dec.com Robert Hagens hagens@cs.wisc.edu Susan Hares skh@merit.edu Manu Kaycee kaycee@trlian.enet.dec.com Paulina Knibbe knibbe@cisco.com Dale Land land@lanl.gov Chao-Yu Liang Shane MacPhillamy slm@netrix.com 3 Bill Manning bmanning@rice.edu Dennis Morris morrisd@imo-uvax.dca.mil Yakov Rekhter yakov@watson.ibm.com Mike Truskowski truskowski@cisco.com Rick Wilder rick@gateway.mitre.org L. Michele Wright uncng!michele@uunet.uu.net 4