Network Working Group F. Baker Request For Comments: 1850 Cisco Systems Obsoletes: 1253 R. Coltun Category: Standards Track RainbowBridge Communications November 1995 OSPF Version 2 Management Information Base Status of this Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Abstract This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in TCP/IP-based internets. In particular, it defines objects for managing the Open Shortest Path First Routing Protocol. Table of Contents 1. The SNMPv2 Network Management Framework .............. 2 1.1 Object Definitions .................................. 3 2. Overview ............................................. 3 2.1 Changes from RFC 1253 ............................... 3 2.2 Textual Conventions ................................. 6 2.3 Structure of MIB .................................... 6 2.3.1 General Variables ................................. 6 2.3.2 Area Data Structure and Area Stub Metric Table .... 7 2.3.3 Link State Database and External Link State Database .......................................... 7 2.3.4 Address Table and Host Tables ..................... 7 2.3.5 Interface and Interface Metric Tables ............. 7 2.3.6 Virtual Interface Table ........................... 7 2.3.7 Neighbor and Virtual Neighbor Tables .............. 7 2.4 Conceptual Row Creation ............................. 7 2.5 Default Configuration ............................... 8 3. Definitions .......................................... 10 3.1 OSPF General Variables .............................. 13 3.2 OSPF Area Table ..................................... 17 Baker & Coltun Standards Track [Page 1] RFC 1850 OSPF MIB November 1995 3.3 OSPF Area Default Metrics ........................... 21 3.4 OSPF Link State Database ............................ 25 3.5 OSPF Address Range Table ............................ 27 3.6 OSPF Host Table ..................................... 29 3.7 OSPF Interface Table ................................ 32 3.8 OSPF Interface Metrics .............................. 39 3.9 OSPF Virtual Interface Table ........................ 42 3.10 OSPF Neighbor Table ................................ 46 3.11 OSPF Virtual Neighbor Table ........................ 51 3.12 OSPF External Link State Database .................. 54 3.13 OSPF Route Table Use ............................... 57 3.14 OSPF Area Aggregate Table .......................... 58 4. OSPF Traps ........................................... 66 4.1 Format Of Trap Definitions .......................... 67 4.2 Approach ............................................ 67 4.3 Ignoring Initial Activity ........................... 67 4.4 Throttling Traps .................................... 67 4.5 One Trap Per OSPF Event ............................. 68 4.6 Polling Event Counters .............................. 68 5. OSPF Trap Definitions ................................ 69 5.1 Trap Support Objects ................................ 69 5.2 Traps ............................................... 71 6. Acknowledgements ...................................... 78 7. References ............................................ 78 8. Security Considerations ............................... 80 9. Authors' Addresses .................................... 80 1. The SNMPv2 Network Management Framework The SNMPv2 Network Management Framework consists of four major components. They are: o RFC 1441 which defines the SMI, the mechanisms used for describing and naming objects for the purpose of management. o STD 17, RFC 1213 defines MIB-II, the core set of managed objects for the Internet suite of protocols. o RFC 1445 which defines the administrative and other architectural aspects of the framework. o RFC 1448 which defines the protocol used for network access to managed objects. The Framework permits new objects to be defined for the purpose of experimentation and evaluation. Baker & Coltun Standards Track [Page 2] RFC 1850 OSPF MIB November 1995 1.1. Object Definitions Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. Objects in the MIB are defined using the subset of Abstract Syntax Notation One (ASN.1) defined in the SMI. In particular, each object object type is named by an OBJECT IDENTIFIER, an administratively assigned name. The object type together with an object instance serves to uniquely identify a specific instantiation of the object. For human convenience, we often use a textual string, termed the descriptor, to refer to the object type. 2. Overview 2.1. Changes from RFC 1253 The changes from RFC 1253 are the following: (1) The textual convention PositiveInteger was changed from 1..'FFFFFFFF'h to 1..'7FFFFFFF'h at the request of Marshall Rose. (2) The textual convention TOSType was changed to reflect the TOS values defined in the Router Requirements Draft, and in accordance with the IP Forwarding Table MIB's values. (3) The names of some objects were changed, conforming to the convention that an acronym (for example, LSA) is a single word ("Lsa") in most SNMP names. (4) textual changes were made to make the MIB readable by Dave Perkins' SMIC MIB Compiler in addition to Mosy. This involved changing the case of some characters in certain names and removing the DEFVAL clauses for Counters. (5) The variables ospfAreaStatus and ospfIfStatus were added, having been overlooked in the original MIB. (6) The range of the variable ospfLsdbType was extended to include multicastLink (Group-membership LSA) and nssaExternalLink (NSSA LSA). (7) The variable ospfIfMetricMetric was renamed ospfIfMetricValue, and the following text was removed from its description: "The value FFFF is distinguished to mean 'no route via Baker & Coltun Standards Track [Page 3] RFC 1850 OSPF MIB November 1995 this TOS'." (8) The variable ospfNbmaNbrPermanence was added, with the values 'dynamic' and 'permanent'; by this means, dynamically learned and configured neighbors can be distinguished. (9) The DESCRIPTION of the variable ospfNbrIpAddr was changed from "The IP address of this neighbor." to "The IP address this neighbor is using in its IP Source Address. Note that, on addressless links, this will not be 0.0.0.0, but the address of another of the neighbor's interfaces." This is by way of clarification and does not change the specification. (10) The OSPF External Link State Database was added. The OSPF Link State Database used to display all LSAs stored; in this MIB, it displays all but the AS External LSAs. This is because there are usually a large number of External LSAs, and they are relicated in all non-Stub Areas. (11) The variable ospfAreaSummary was added to control the import of summary LSAs into stub areas. If it is noAreaSummary (default) the router will neither originate nor propagate summary LSAs into the stub area. It will rely entirely on its default route. If it is sendAreaSummary, the router will both summarize and propagate summary LSAs. (12) The general variables ospfExtLsdbLimit and ExitOverflowInterval were introduced to help handle LSDB overflow. (13) The use of the IP Forwarding Table is defined. (14) The ospfAreaRangeTable was obsoleted and replaced with the ospfAreaAggregateTable to accommodate two additional indexes. The ospfAreaAggregateEntry keys now include a LsdbType (which can be used to differentiate between the traditional type-3 Aggregates and NSSA Aggregates) and an Baker & Coltun Standards Track [Page 4] RFC 1850 OSPF MIB November 1995 ospfAreaAggregateMask (which will more clearly express the range). (15) The variable ospfAreaAggregateEffect was added. This permits the network manager to hide a subnet within an area. (16) Normally, the border router of a stub area advertises a default route as an OSPF network summary. An NSSA border router will generate a type-7 LSA indicating a default route, and import it into the NSSA. ospfStubMetricType (ospf internal, type 1 external, or type 2 external) indicates the type of the default metric advertised. (17) ospfMulticastExtensions is added to the OSPF General Group. This indicates the router's ability to forward IP multicast (Class D) datagrams. (18) ospfIfMulticastForwarding is added to the Interface Group. It indicates whether, and if so, how, multicasts should be forwarded on the interface. (19) The MIB is converted to SNMP Version 2. Beyond simple text changes and the addition of the MODULE-IDENTITY and MODULE-COMPLIANCE macros, this involved trading the TruthValue Textual Convention for SNMP Version 2's, which has the same values, and trading the Validation Textual Convention for SNMP Version 2's RowStatus. (20) ospfAuthType (area authentication type) was changed to an interface authentication type to match the key. It also has an additional value, to indicate the use of MD5 for authentication. (21) ospfIfIntfType has a new value, pointToMultipoint. (22) ospfIfDemand (read/write) is added, to permit control of Demand OSPF features. (23) ospfNbrHelloSuppressed and ospfVirtNbrHelloSuppressed were added, (read only). They indicate whether Hellos are being suppressed to the neighbor. (24) ospfDemandExtensions was added to indicate whether the Demand OSPF extensions have been implemented, and to disable them if appropriate. Baker & Coltun Standards Track [Page 5] RFC 1850 OSPF MIB November 1995 2.2. Textual Conventions Several new data types are introduced as a textual convention in this MIB document. These textual conventions enhance the readability of the specification and can ease comparison with other specifications if appropriate. It should be noted that the introduction of the these textual conventions has no effect on either the syntax nor the semantics of any managed objects. The use of these is merely an artifact of the explanatory method used. Objects defined in terms of one of these methods are always encoded by means of the rules that define the primitive type. Hence, no changes to the SMI or the SNMP are necessary to accommodate these textual conventions which are adopted merely for the convenience of readers and writers in pursuit of the elusive goal of clear, concise, and unambiguous MIB documents. The new data types are AreaID, RouterID, TOSType, Metric, BigMetric, Status, PositiveInteger, HelloRange, UpToMaxAge, InterfaceIndex, and DesignatedRouterPriority. 2.3. Structure of MIB The MIB is composed of the following sections: General Variables Area Data Structure Area Stub Metric Table Link State Database Address Range Table Host Table Interface Table Interface Metric Table Virtual Interface Table Neighbor Table Virtual Neighbor Table External Link State Database Aggregate Range Table There exists a separate MIB for notifications ("traps"), which is entirely optional. 2.3.1. General Variables The General Variables are about what they sound like; variables which are global to the OSPF Process. Baker & Coltun Standards Track [Page 6] RFC 1850 OSPF MIB November 1995 2.3.2. Area Data Structure and Area Stub Metric Table The Area Data Structure describes the OSPF Areas that the router participates in. The Area Stub Metric Table describes the metrics advertised into a stub area by the default router(s). 2.3.3. Link State Database and External Link State Database The Link State Database is provided primarily to provide detailed information for network debugging. 2.3.4. Address Table and Host Tables The Address Range Table and Host Table are provided to view configured Network Summary and Host Route information. 2.3.5. Interface and Interface Metric Tables The Interface Table and the Interface Metric Table together describe the various IP interfaces to OSPF. The metrics are placed in separate tables in order to simplify dealing with multiple types of service, and to provide flexibility in the event that the IP TOS definition is changed in the future. A Default Value specification is supplied for the TOS 0 (default) metric. 2.3.6. Virtual Interface Table Likewise, the Virtual Interface Table describe virtual links to the OSPF Process. 2.3.7. Neighbor and Virtual Neighbor Tables The Neighbor Table and the Virtual Neighbor Table describe the neighbors to the OSPF Process. 2.4. Conceptual Row Creation For the benefit of row-creation in "conceptual" (see [9]) tables, DEFVAL (Default Value) clauses are included in the definitions in section 3, suggesting values which an agent should use for instances of variables which need to be created due to a Set-Request, but which are not specified in the Set-Request. DEFVAL clauses have not been specified for some objects which are read-only, implying that they are zeroed upon row creation. These objects are of the SYNTAX Counter32 or Gauge32. For those objects not having a DEFVAL clause, both management stations and agents should heed the Robustness Principle of the Baker & Coltun Standards Track [Page 7] RFC 1850 OSPF MIB November 1995 Internet (see RFC-791): "be liberal in what you accept, conservative in what you send" That is, management stations should include as many of these columnar objects as possible (e.g., all read-write objects) in a Set-Request when creating a conceptual row; agents should accept a Set-Request with as few of these as they need (e.g., the minimum contents of a row creating SET consists of those objects for which, as they cannot be intuited, no default is specified.). There are numerous read-write objects in this MIB, as it is designed for SNMP management of the protocol, not just SNMP monitoring of its state. However, in the absence of a standard SNMP Security architecture, it is acceptable for implementations to implement these as read-only with an alternative interface for their modification. 2.5. Default Configuration OSPF is a powerful routing protocol, equipped with features to handle virtually any configuration requirement that migh