This document is obsolete. Please
refer to RFC 1252.
Network Working Group F. Baker Request for Comments: 1248 ACC R. Coltun Computer Science Center July 1991
OSPF Version 2 Management Information Base
Status of this Memo
This RFC specifies an IAB standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "IAB Official Protocol Standards" for the standardization state and status of this protocol. Distribution of this memo is unlimited.
Table of Contents
1. Abstract ............................................. 2 2. The Network Management Framework...................... 2 3. Objects .............................................. 2 3.1 Format of Definitions ............................... 3 4. Overview ............................................. 3 4.1 Textual Conventions ................................. 3 4.2 Structure of MIB .................................... 3 4.2.1 General Variables ................................. 4 4.2.2 Area Data Structure and Area Stub Metric Table .... 4 4.2.3 Link State Database ............................... 4 4.2.4 Address Table and Host Tables ..................... 4 4.2.5 Interface and Interface Metric Tables ............. 4 4.2.6 Virtual Interface Table ........................... 4 4.2.7 Neighbor and Virtual Neighbor Tables .............. 4 4.3 Conceptual Row Creation ............................. 5 4.4 Default Configuration ............................... 5 5. Definitions .......................................... 7 5.1 OSPF General Variables .............................. 8 5.2 OSPF Area Data Structure ............................ 11 5.3 OSPF Area Default Metric Table ...................... 14 5.4 OSPF Link State Database ............................ 16 5.5 OSPF Address Range Table ............................ 19 5.6 OSPF Host Table ..................................... 21 5.7 OSPF Interface Table ................................ 23 5.8 OSPF Interface Metric Table ......................... 28 5.9 OSPF Virtual Interface Table ........................ 31 5.10 OSPF Neighbor Table ................................ 34 5.11 OSPF Virtual Neighbor Table ........................ 38 6. Acknowledgements ..................................... 40
This memo defines an experimental 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 OSPF Version 2.
The Internet-standard Network Management Framework consists of three components. They are:
RFC 1155 which defines the SMI, the mechanisms used for describing and naming objects for the purpose of management. RFC 1212 defines a more concise description mechanism, which is wholly consistent with the SMI.
RFC 1156 which defines MIB-I, the core set of managed objects for the Internet suite of protocols. RFC 1213, defines MIB-II, an evolution of MIB-I based on implementation experience and new operational requirements.
RFC 1157 which defines the SNMP, the protocol used for network access to managed objects.
The Framework permits new objects to be defined for the purpose of experimentation and evaluation.
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) [7] defined in the SMI. In particular, each object has a name, a syntax, and an encoding. The name is an object identifier, an administratively assigned name, which specifies an object type. 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 OBJECT DESCRIPTOR, to also refer to the object type.
The syntax of an object type defines the abstract data structure corresponding to that object type. The ASN.1 language is used for this purpose. However, the SMI [3] purposely restricts the ASN.1
Baker & Coltun [Page 2]
RFC 1248 OSPF Version 2 MIB July 1991
constructs which may be used. These restrictions are explicitly made for simplicity.
The encoding of an object type is simply how that object type is represented using the object type's syntax. Implicitly tied to the notion of an object type's syntax and encoding is how the object type is represented when being transmitted on the network.
The SMI specifies the use of the basic encoding rules of ASN.1 [8], subject to the additional requirements imposed by the SNMP.
Section 5 contains contains the specification of all object types contained in this MIB module. The object types are defined using the conventions defined in the SMI, as amended by the extensions specified in [9].
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, TruthValue, Status, Validation, PositiveInteger, HelloRange, UpToMaxAge, InterfaceIndex, and DesignatedRouterPriority.
The General Variables are about what they sound like; variables which are global to the OSPF Process.
4.2.2. 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).
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.
For the benefit of row-creation in "conceptual" (see [9]) tables, DEFVAL (Default Value) clauses are included in the definitions in section 5, 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 Counter or Gauge.
For those objects not having a DEFVAL clause, both management stations and agents should heed the Robustness Principle of the 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.
OSPF is a powerful routing protocol, equipped with features to handle virtually any configuration requirement that might reasonably be found within an Autonomous System. With this power comes a fair degree of complexity, which the sheer number of objects in the MIB will attest to. Care has therefore been taken, in constructing this MIB, to define default values for virtually every object, to minimize the amount of parameterization required in the typical case. That default configuration is as follows:
Given the following assumptions:
- IP has already been configured
- The ifTable has already been configured
Baker & Coltun [Page 5]
RFC 1248 OSPF Version 2 MIB July 1991
- ifSpeed is estimated by the interface drivers
- The OSPF Process automatically discovers all IP Interfaces and creates corresponding OSPF Interfaces
- The TOS 0 metrics are autonomously derived from ifSpeed
- The OSPF Process automatically creates the Areas required for the Interfaces
The simplest configuration of an OSPF process requires that:
- The OSPF Process be Enabled.
This can be accomplished with a single SET:
ospfAdminStat := enabled.
The configured system will have the following attributes:
- The RouterID will be one of the IP addresses of the device
- The device will be neither an Area Border Router nor an Autonomous System Border Router.
- Every IP Interface, with or without an address, will be an OSPF Interface.
- The AreaID of each interface will be 0.0.0.0, the Backbone.
- Authentication will be disabled
- All Broadcast and Point to Point interfaces will be operational. NBMA Interfaces require the configuration of at least one neighbor.
- Timers on all direct interfaces will be: Hello Interval: 10 seconds Dead Timeout: 40 Seconds Retransmission: 5 Seconds Transit Delay: 1 Second Poll Interval: 120 Seconds
- no direct links to hosts will be configured.
Baker & Coltun [Page 6]
RFC 1248 OSPF Version 2 MIB July 1991
- no addresses will be summarized
- Metrics, being a measure of bit duration, are unambiguous and intelligent.
IMPORTS experimental, Counter, Gauge, IpAddress FROM RFC1155-SMI OBJECT-TYPE FROM RFC-1212;
-- This MIB module uses the extended OBJECT-TYPE macro as -- defined in [9].
ospf OBJECT IDENTIFIER ::= { standard-mib 13 }
-- The Area ID, in OSPF, has the same format as an IP Address, -- but has the function of defining a summarization point for -- Link State Advertisements
AreaID ::= IpAddress
-- The Router ID, in OSPF, has the same format as an IP Address, -- but identifies the router independent of its IP Address.
RouterID ::= IpAddress
-- The OSPF Metric is defined as an unsigned value in the range
-- Potential Priorities for the Designated Router Election
DesignatedRouterPriority ::= INTEGER (0..'FF'h)
-- Type of Service is defined as a mapping to the IP Type of -- Service Flags as defined in the Router Requirements -- Document: -- -- D => Low Delay R => Reliable Route -- T => High Bandwidth
-- D T R TOS D T R TOS -- 0 0 0 => 0 0 0 1 => 4 -- 0 1 0 => 8 0 1 1 => 12 -- 1 0 0 => 16 1 0 1 => 20 -- 1 1 0 => 24 1 1 1 => 28
-- The remaining values are left for future definition.
TOSType ::= INTEGER (0..31)
-- OSPF General Variables
-- These parameters apply globally to the Router's -- OSPF Process.
ospfGeneralGroup OBJECT IDENTIFIER ::= { ospf 1 }
ospfRouterId OBJECT-TYPE SYNTAX RouterID ACCESS read-write STATUS mandatory DESCRIPTION "A 32-bit integer uniquely identifying the router in
Baker & Coltun [Page 8]
RFC 1248 OSPF Version 2 MIB July 1991
the Autonomous System.
By convention, to ensure uniqueness, this should default to the value of one of the router's IP interface addresses." REFERENCE "OSPF Version 2, C.1 Global parameters" ::= { ospfGeneralGroup 1 }
ospfAdminStat OBJECT-TYPE SYNTAX Status ACCESS read-write STATUS mandatory DESCRIPTION "The administrative status of OSPF in the router. The value 'enabled' denotes that the OSPF Process is active on at least one interface; 'disabled' disables it on all interfaces." ::= { ospfGeneralGroup 2 }
ospfVersionNumber OBJECT-TYPE SYNTAX INTEGER { version2 (2) } ACCESS read-only STATUS mandatory DESCRIPTION "The current version number of the OSPF protocol is 2." REFERENCE "OSPF Version 2, Title" ::= { ospfGeneralGroup 3 }
ospfAreaBdrRtrStatus OBJECT-TYPE SYNTAX TruthValue ACCESS read-only STATUS mandatory DESCRIPTION "A flag to note whether this router is an area border router." REFERENCE "OSPF Version 2, Section 3 Splitting the AS into Areas" ::= { ospfGeneralGroup 4 }
ospfASBdrRtrStatus OBJECT-TYPE SYNTAX TruthValue ACCESS read-write STATUS mandatory DESCRIPTION "A flag to note whether this router is an Autonomous System border router."
Baker & Coltun [Page 9]
RFC 1248 OSPF Version 2 MIB July 1991
REFERENCE "OSPF Version 2, Section 3.3 Classification of routers" ::= { ospfGeneralGroup 5 }
ospfExternLSACount OBJECT-TYPE SYNTAX Gauge ACCESS read-only STATUS mandatory DESCRIPTION "The number of external (LS type 5) link-state advertisements in the link-state database." REFERENCE "OSPF Version 2, Appendix A.4.5 AS external link advertisements" ::= { ospfGeneralGroup 6 }
ospfExternLSACksumSum OBJECT-TYPE SYNTAX INTEGER ACCESS read-only STATUS mandatory DESCRIPTION "The 32-bit unsigned sum of the LS checksums of the external link-state advertisements contained in the link-state database. This sum can be used to determine if there has been a change in a router's link state database, and to compare the link-state database of two routers." ::= { ospfGeneralGroup 7 }
ospfTOSSupport OBJECT-TYPE SYNTAX TruthValue ACCESS read-write STATUS mandatory DESCRIPTION "The router's support for type-of-service routing." REFERENCE "OSPF Version 2, Appendix F.1.2 Optional TOS support" ::= { ospfGeneralGroup 8 }
ospfOriginateNewLSAs OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of new link-state advertisements that have been originated. This number is incremented each time the router originates a new LSA." ::= { ospfGeneralGroup 9 }
Baker & Coltun [Page 10]
RFC 1248 OSPF Version 2 MIB July 1991
ospfRxNewLSAs OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of link-state advertisements received determined to be new instantiations. This number does not include newer instantiations of self-originated link-state advertisements." ::= { ospfGeneralGroup 10 }
-- The OSPF Area Data Structure contains information -- regarding the various areas. The interfaces and -- virtual links are configured as part of these areas. -- Area 0.0.0.0, by definition, is the Backbone Area
ospfAreaTable OBJECT-TYPE SYNTAX SEQUENCE OF OspfAreaEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "Information describing the configured parameters and cumulative statistics of the router's attached areas." REFERENCE "OSPF Version 2, Section 6 The Area Data Structure" ::= { ospf 2 }
ospfAreaEntry OBJECT-TYPE SYNTAX OspfAreaEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "Information describing the configured parameters and cumulative statistics of one of the router's attached areas." INDEX { ospfAreaID } ::= { ospfAreaTable 1 }
ospfAreaId OBJECT-TYPE SYNTAX AreaID ACCESS read-write STATUS mandatory DESCRIPTION "A 32-bit integer uniquely identifying an area. Area ID 0.0.0.0 is used for the OSPF backbone." REFERENCE "OSPF Version 2, Appendix C.2 Area parameters" ::= { ospfAreaEntry 1 }
ospfAuthType OBJECT-TYPE SYNTAX INTEGER -- none (0), -- simplePassword (1) -- reserved for specification by IANA (> 1) ACCESS read-write STATUS mandatory DESCRIPTION "The authentication type specified for an area. Additional authentication types may be assigned locally on a per Area basis." REFERENCE "OSPF Version 2, Appendix E Authentication" DEFVAL { 0 } -- no authentication, by default ::= { ospfAreaEntry 2 }
ospfImportASExtern OBJECT-TYPE SYNTAX TruthValue ACCESS read-write STATUS mandatory DESCRIPTION "The area's support for importing AS external link- state advertisements." REFERENCE "OSPF Version 2, Appendix C.2 Area parameters" DEFVAL { true }
Baker & Coltun [Page 12]
RFC 1248 OSPF Version 2 MIB July 1991
::= { ospfAreaEntry 3 }
ospfSpfRuns OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of times that the intra-area route table has been calculated using this area's link-state database. This is typically done using Dijkstra's algorithm." DEFVAL { 0 } ::= { ospfAreaEntry 4 }
ospfAreaBdrRtrCount OBJECT-TYPE SYNTAX Gauge ACCESS read-only STATUS mandatory DESCRIPTION "The total number of area border routers reachable within this area. This is initially zero, and is calculated in each SPF Pass." DEFVAL { 0 } ::= { ospfAreaEntry 5 }
ospfASBdrRtrCount OBJECT-TYPE SYNTAX Gauge ACCESS read-only STATUS mandatory DESCRIPTION "The total number of Autonomous System border routers reachable within this area. This is initially zero, and is calculated in each SPF Pass." DEFVAL { 0 } ::= { ospfAreaEntry 6 }
ospfAreaLSACount OBJECT-TYPE SYNTAX Gauge ACCESS read-only STATUS mandatory DESCRIPTION "The total number of link-state advertisements in this area's link-state database, excluding AS External LSA's." DEFVAL { 0 } ::= { ospfAreaEntry 7 }
Baker & Coltun [Page 13]
RFC 1248 OSPF Version 2 MIB July 1991
ospfAreaLSACksumSum OBJECT-TYPE SYNTAX INTEGER ACCESS read-only STATUS mandatory DESCRIPTION "The 32-bit unsigned sum of the link-state advertisements' LS checksums contained in this area's link-state database. This sum excludes external (LS type 5) link-state advertisements. The sum can be used to determine if there has been a change in a router's link state database, and to compare the link-state database of two routers." DEFVAL { 0 } ::= { ospfAreaEntry 8 }
-- OSPF Area Default Metric Table
-- The OSPF Area Default Metric Table describes the metrics -- that a default Area Border Router will advertise into a -- Stub area.
ospfStubAreaTable OBJECT-TYPE SYNTAX SEQUENCE OF OspfStubAreaEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The set of metrics that will be advertised by a default Area Border Router into a stub area." REFERENCE "OSPF Version 2, Appendix C.2, Area Parameters" ::= { ospf 3 }
ospfStubAreaEntry OBJECT-TYPE SYNTAX OspfStubAreaEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The metric for a given Type of Service that will be advertised by a default Area Border Router into a stub area." REFERENCE "OSPF Version 2, Appendix C.2, Area Parameters" INDEX { ospfStubAreaID, ospfStubTOS } ::= { ospfStubAreaTable 1 }
ospfStubAreaID OBJECT-TYPE SYNTAX AreaID ACCESS read-write STATUS mandatory DESCRIPTION "The 32 bit identifier for the Stub Area. On creation, this can be derived from the instance." ::= { ospfStubAreaEntry 1 }
ospfStubTOS OBJECT-TYPE SYNTAX TOSType ACCESS read-write STATUS mandatory DESCRIPTION "The Type of Service associated with the metric. On creation, this can be derived from the instance."
::= { ospfStubAreaEntry 2 }
ospfStubMetric OBJECT-TYPE SYNTAX BigMetric ACCESS read-write STATUS mandatory DESCRIPTION "The metric value applied at the indicated type of service. By default, this equals the least metric at the type of service among the interfaces to other areas." ::= { ospfStubAreaEntry 3 }
ospfStubStatus OBJECT-TYPE SYNTAX Validation ACCESS read-write STATUS mandatory DESCRIPTION "This variable displays the validity or invalidity of
Baker & Coltun [Page 15]
RFC 1248 OSPF Version 2 MIB July 1991
the entry. Setting it to 'invalid' has the effect of rendering it inoperative. The internal effect (row removal) is implementation dependent." DEFVAL { valid } ::= { ospfStubAreaEntry 4 }
-- OSPF Link State Database
-- The Link State Database contains the Link State -- Advertisements from throughout the areas that the -- device is attached to.
ospfLsdbTable OBJECT-TYPE SYNTAX SEQUENCE OF OspfLsdbEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The OSPF Process's Links State Database." REFERENCE "OSPF Version 2, Section 12 Link State Advertisements" ::= { ospf 4 }
ospfLsdbEntry OBJECT-TYPE SYNTAX OspfLsdbEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A single Link State Advertisement." INDEX { ospfLsdbAreaId, ospfLsdbType, ospfLsdbLSID, ospfLsdbRouterId } ::= { ospfLsdbTable 1 }
ospfLsdbAreaId OBJECT-TYPE SYNTAX AreaID ACCESS read-only STATUS mandatory DESCRIPTION "The 32 bit identifier of the Area from which the LSA was received." REFERENCE "OSPF Version 2, Appendix C.2 Area parameters" ::= { ospfLsdbEntry 1 }
ospfLsdbType OBJECT-TYPE SYNTAX INTEGER { routerLink (1), networkLink (2), summaryLink (3), asSummaryLink (4), asExternalLink (5) } ACCESS read-only STATUS mandatory DESCRIPTION "The type of the link state advertisement. Each link state type has a separate advertisement format." REFERENCE "OSPF Version 2, Appendix A.4.1 The Link State Advertisement header" ::= { ospfLsdbEntry 2 }
ospfLsdbLSID OBJECT-TYPE SYNTAX IpAddress ACCESS read-only STATUS mandatory DESCRIPTION "The Link State ID is an LS Type Specific field containing either a Router ID or an IP Address; it identifies the piece of the routing domain that is being described by the advertisement." REFERENCE "OSPF Version 2, Section 12.1.4 Link State ID" ::= { ospfLsdbEntry 3 }
Baker & Coltun [Page 17]
RFC 1248 OSPF Version 2 MIB July 1991
ospfLsdbRouterId OBJECT-TYPE SYNTAX RouterID ACCESS read-only STATUS mandatory DESCRIPTION "The 32 bit number that uniquely identifies the originating router in the Autonomous System." REFERENCE "OSPF Version 2, Appendix C.1 Global parameters" ::= { ospfLsdbEntry 4 }
-- Note that the OSPF Sequence Number is a 32 bit signed -- integer. It starts with the value '80000001'h, -- or -'7FFFFFFF'h, and increments until '7FFFFFFF'h -- Thus, a typical sequence number will be very negative.
ospfLsdbSequence OBJECT-TYPE SYNTAX INTEGER ACCESS read-only STATUS mandatory DESCRIPTION "The sequence number field is a signed 32-bit integer. It is used to detect old and duplicate link state advertisements. The space of sequence numbers is linearly ordered. The larger the sequence number the more recent the advertisement." REFERENCE "OSPF Version 2, Section 12.1.6 LS sequence number" ::= { ospfLsdbEntry 5 }
ospfLsdbAge OBJECT-TYPE SYNTAX INTEGER -- Should be 0..MaxAge ACCESS read-only STATUS mandatory DESCRIPTION "This field is the age of the link state advertisement in seconds." REFERENCE "OSPF Version 2, Section 12.1.1 LS age" ::= { ospfLsdbEntry 6 }
ospfLsdbChecksum OBJECT-TYPE SYNTAX INTEGER ACCESS read-only STATUS mandatory DESCRIPTION "This field is the checksum of the complete contents of the advertisement, excepting the age field. The age
Baker & Coltun [Page 18]
RFC 1248 OSPF Version 2 MIB July 1991
field is excepted so that an advertisement's age can be incremented without updating the checksum. The checksum used is the same that is used for ISO connectionless datagrams; it is commonly referred to as the Fletcher checksum." REFERENCE "OSPF Version 2, Section 12.1.7 LS checksum" ::= { ospfLsdbEntry 7 }
ospfLsdbAdvertisement OBJECT-TYPE SYNTAX OCTET STRING ACCESS read-only STATUS mandatory DESCRIPTION "The entire Link State Advertisement, including its header." REFERENCE "OSPF Version 2, Section 12 Link State Advertisements" ::= { ospfLsdbEntry 8 }
-- Address Range Table
-- The Address Range Table acts as an adjunct to the Area -- Table; It describes those Address Range Summaries that -- are configured to be propagated from an Area to reduce -- the amount of information about it which is known beyond -- its borders.
ospfAreaRangeTable OBJECT-TYPE SYNTAX SEQUENCE OF OspfAreaRangeEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A range if IP addresses specified by an IP address/IP network mask pair. For example, class B address range of X.X.X.X with a network mask of 255.255.0.0 includes all IP addresses from X.X.0.0 to X.X.255.255" REFERENCE "OSPF Version 2, Appendix C.2 Area parameters" ::= { ospf 5 }
ospfAreaRangeEntry OBJECT-TYPE SYNTAX OspfAreaRangeEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A range if IP addresses specified by an IP address/IP
Baker & Coltun [Page 19]
RFC 1248 OSPF Version 2 MIB July 1991
network mask pair. For example, class B address range of X.X.X.X with a network mask of 255.255.0.0 includes all IP addresses from X.X.0.0 to X.X.255.255" REFERENCE "OSPF Version 2, Appendix C.2 Area parameters" INDEX { ospfAreaRangeAreaID, ospfAreaRangeNet } ::= { ospfAreaRangeTable 1 }
ospfAreaRangeAreaID OBJECT-TYPE SYNTAX AreaID ACCESS read-write STATUS mandatory DESCRIPTION "The Area the Address Range is to be found within." REFERENCE "OSPF Version 2, Appendix C.2 Area parameters" ::= { ospfAreaRangeEntry 1 }
ospfAreaRangeNet OBJECT-TYPE SYNTAX IpAddress ACCESS read-write STATUS mandatory DESCRIPTION "The IP Address of the Net or Subnet indicated by the range." REFERENCE "OSPF Version 2, Appendix C.2 Area parameters" ::= { ospfAreaRangeEntry 2 }
ospfAreaRangeMask OBJECT-TYPE SYNTAX IpAddress ACCESS read-write STATUS mandatory DESCRIPTION "The Subnet Mask that pertains to the Net or Subnet." REFERENCE
Baker & Coltun [Page 20]
RFC 1248 OSPF Version 2 MIB July 1991
"OSPF Version 2, Appendix C.2 Area parameters" ::= { ospfAreaRangeEntry 3 }
ospfAreaRangeStatus OBJECT-TYPE SYNTAX Validation ACCESS read-write STATUS mandatory DESCRIPTION "This variable displays the validity or invalidity of the entry. Setting it to 'invalid' has the effect of rendering it inoperative. The internal effect (row removal) is implementation dependent." DEFVAL { valid } ::= { ospfAreaRangeEntry 4 }
-- OSPF Host Table
-- The Host/Metric Table indicates what hosts are directly -- attached to the Router, and what metrics and types of -- service should be advertised for them.
ospfHostTable OBJECT-TYPE SYNTAX SEQUENCE OF OspfHostEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The list of Hosts, and their metrics, that the router will advertise as host routes." REFERENCE "OSPF Version 2, Appendix C.6 Host route parameters" ::= { ospf 6 }
ospfHostEntry OBJECT-TYPE SYNTAX OspfHostEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A metric to be advertised, for a given type of service, when a given host is reachable." INDEX { ospfHostIpAddress, ospfHostTOS } ::= { ospfHostTable 1 }
ospfHostIpAddress OBJECT-TYPE SYNTAX IpAddress ACCESS read-write STATUS mandatory DESCRIPTION "The IP Address of the Host." REFERENCE "OSPF Version 2, Appendix C.6 Host route parameters" ::= { ospfHostEntry 1 }
ospfHostTOS OBJECT-TYPE SYNTAX TOSType ACCESS read-write STATUS mandatory DESCRIPTION "The Type of Service of the route being configured." REFERENCE "OSPF Version 2, Appendix C.6 Host route parameters" ::= { ospfHostEntry 2 }
ospfHostMetric OBJECT-TYPE SYNTAX Metric ACCESS read-write STATUS mandatory DESCRIPTION "The Metric to be advertised." REFERENCE "OSPF Version 2, Appendix C.6 Host route parameters" ::= { ospfHostEntry 3 }
ospfHostStatus OBJECT-TYPE SYNTAX Validation ACCESS read-write STATUS mandatory DESCRIPTION "This variable displays the validity or invalidity of the entry. Setting it to 'invalid' has the effect of rendering it inoperative. The internal effect (row removal) is implementation dependent." DEFVAL { valid } ::= { ospfHostEntry 4 }
Baker & Coltun [Page 22]
RFC 1248 OSPF Version 2 MIB July 1991
-- OSPF Interface Table
-- The OSPF Interface Table augments the ifTable with OSPF -- specific information.
ospfIfTable OBJECT-TYPE SYNTAX SEQUENCE OF OspfIfEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The OSPF Interface Table describes the interfaces from the viewpoint of OSPF." REFERENCE "OSPF Version 2, Appendix C.3 Router interface parameters" ::= { ospf 7 }
ospfIfEntry OBJECT-TYPE SYNTAX OspfIfEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The OSPF Interface Entry describes one interface from the viewpoint of OSPF." INDEX { ospfIfIpAddress, ospfAddressLessIf } ::= { ospfIfTable 1 }
ospfIfIpAddress OBJECT-TYPE SYNTAX IpAddress ACCESS read-write STATUS mandatory DESCRIPTION "The IP address of this OSPF interface." ::= { ospfIfEntry 1 }
ospfAddressLessIf OBJECT-TYPE SYNTAX INTEGER ACCESS read-write STATUS mandatory DESCRIPTION "For the purpose of easing the instancing of addressed and addressless interfaces; This variable takes the value 0 on interfaces with IP Addresses, and the corresponding value of ifIndex for interfaces having no IP Address." ::= { ospfIfEntry 2 }
ospfIfAreaId OBJECT-TYPE SYNTAX AreaID ACCESS read-write STATUS mandatory DESCRIPTION "A 32-bit integer uniquely identifying the area to which the interface connects. Area ID 0.0.0.0 is used for the OSPF backbone." DEFVAL { '00000000'H } -- 0.0.0.0 ::= { ospfIfEntry 3 }
By way of a default, this field may be intuited from the corresponding value of ifType. Broadcast LANs, such as Ethernet and IEEE 802.5, take the value 'broadcast', X.25, Frame Relay, and similar technologies take the value 'nbma', and links that are definitively point to point take the value 'pointToPoint'." ::= { ospfIfEntry 4 }
ospfIfAdminStat OBJECT-TYPE SYNTAX Status ACCESS read-write STATUS mandatory DESCRIPTION "The OSPF interface's administrative status. The value 'enabled' denotes that neighbor relationships may be formed on the interface, and the interface will be advertised as an internal route to some area. The value 'disabled' denotes that the interface is external to OSPF." DEFVAL { enabled } ::= { ospfIfEntry 5 }
ospfIfRtrPriority OBJECT-TYPE SYNTAX DesignatedRouterPriority ACCESS read-write STATUS mandatory DESCRIPTION "The priority of this interface. Used in multi-access networks, this field is used in the designated router election algorithm. The value 0 signifies that the router is not eligible to become the designated router on this particular network. In the event of a tie in this value, routers will use their router id as a tie breaker." DEFVAL { 1 } ::= { ospfIfEntry 6 }
Baker & Coltun [Page 25]
RFC 1248 OSPF Version 2 MIB July 1991
ospfIfTransitDelay OBJECT-TYPE SYNTAX UpToMaxAge ACCESS read-write STATUS mandatory DESCRIPTION "The estimated number of seconds it takes to transmit a link- state update packet over this interface." DEFVAL { 1 } ::= { ospfIfEntry 7 }
ospfIfRetransInterval OBJECT-TYPE SYNTAX UpToMaxAge ACCESS read-write STATUS mandatory DESCRIPTION "The number of seconds between link-state advertisement retransmissions, for adjacencies belonging to this interface. This value is also used when retransmitting database description and link-state request packets." DEFVAL { 5 } ::= { ospfIfEntry 8 }
ospfIfHelloInterval OBJECT-TYPE SYNTAX HelloRange ACCESS read-write STATUS mandatory DESCRIPTION "The length of time, in seconds, between the Hello packets that the router sends on the interface. This value must be the same for all routers attached to a common network." DEFVAL { 10 } ::= { ospfIfEntry 9 }
ospfIfRtrDeadInterval OBJECT-TYPE SYNTAX PositiveInteger ACCESS read-write STATUS mandatory DESCRIPTION "The number of seconds that a router's Hello packets have not been seen before it's neighbors declare the router down. This should be some multiple of the Hello interval. This value must be the same for all routers attached to a common network." DEFVAL { 40 } ::= { ospfIfEntry 10 }
Baker & Coltun [Page 26]
RFC 1248 OSPF Version 2 MIB July 1991
ospfIfPollInterval OBJECT-TYPE SYNTAX PositiveInteger ACCESS read-write STATUS mandatory DESCRIPTION "The larger time interval, in seconds, between the Hello packets sent to an inactive non-broadcast multi- access neighbor." DEFVAL { 120 } ::= { ospfIfEntry 11 }
ospfIfState OBJECT-TYPE SYNTAX INTEGER { down (1), loopback (2), waiting (3), pointToPoint (4), designatedRouter (5), backupDesignatedRouter (6), otherDesignatedRouter (7) } ACCESS read-only STATUS mandatory DESCRIPTION "The OSPF Interface State." DEFVAL { down } ::= { ospfIfEntry 12 }
ospfIfDesignatedRouter OBJECT-TYPE SYNTAX IpAddress ACCESS read-only STATUS mandatory DESCRIPTION "The IP Address of the Designated Router." DEFVAL { '00000000'H } -- 0.0.0.0 ::= { ospfIfEntry 13 }
ospfIfBackupDesignatedRouter OBJECT-TYPE SYNTAX IpAddress ACCESS read-only STATUS mandatory DESCRIPTION "The IP Address of the Backup Designated Router." DEFVAL { '00000000'H } -- 0.0.0.0 ::= { ospfIfEntry 14 }
Baker & Coltun [Page 27]
RFC 1248 OSPF Version 2 MIB July 1991
ospfIfEvents OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of times this OSPF interface has changed its state, or an error has occurred." DEFVAL { 0 } ::= { ospfIfEntry 15 }
ospfIfAuthKey OBJECT-TYPE SYNTAX OCTET STRING ACCESS read-write STATUS mandatory DESCRIPTION "The Authentication Key. If the Area's Authorization Type is simplePassword, and the key length is shorter than 8 octets, the agent will left adjust and zero fill to 8 octets.
When read, ospfIfAuthKey always returns an Octet String of length zero." REFERENCE "OSPF Version 2, Section 9 The Interface Data Structure" DEFVAL { '0000000000000000'H } -- 0.0.0.0.0.0.0.0 ::= { ospfIfEntry 16 }
-- OSPF Interface Metric Table
-- The Metric Table describes the metrics to be advertised -- for a specified interface at the various types of service. -- As such, this table is an adjunct of the OSPF Interface -- Table.
-- Types of service, as defined by RFC 791, have the ability -- to request low delay, high bandwidth, or reliable linkage.
-- For the purposes of this specification, the measure of -- bandwidth
-- Metric = 10^8 / ifSpeed
-- is the default value. For multiple link interfaces, note -- that ifSpeed is the sum of the individual link speeds. -- This yields a number having the following typical values:
-- Routes that are not specified use the default (TOS 0) metric
ospfIfMetricTable OBJECT-TYPE SYNTAX SEQUENCE OF OspfIfMetricEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The TOS metrics for a non-virtual interface identified by the interface index." REFERENCE "OSPF Version 2, Appendix C.3 Router interface parameters" ::= { ospf 8 }
ospfIfMetricEntry OBJECT-TYPE SYNTAX OspfIfMetricEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A particular TOS metric for a non-virtual interface identified by the interface index." REFERENCE "OSPF Version 2, Appendix C.3 Router interface parameters" INDEX { ospfIfMetricIpAddress, ospfIfMetricAddressLessIf, ospfIfMetricTOS } ::= { ospfIfMetricTable 1 }
ospfIfMetricIpAddress OBJECT-TYPE SYNTAX IpAddress ACCESS read-write STATUS mandatory DESCRIPTION "The IP address of this OSPF interface. On row creation, this can be derived from the instance." ::= { ospfIfMetricEntry 1 }
ospfIfMetricAddressLessIf OBJECT-TYPE SYNTAX INTEGER ACCESS read-write STATUS mandatory DESCRIPTION "For the purpose of easing the instancing of addressed and addressless interfaces; This variable takes the value 0 on interfaces with IP Addresses, and the value of ifIndex for interfaces having no IP Address. On row creation, this can be derived from the instance." ::= { ospfIfMetricEntry 2 }
ospfIfMetricTOS OBJECT-TYPE SYNTAX TOSType ACCESS read-write STATUS mandatory DESCRIPTION "The type of service metric being referenced. On row creation, this can be derived from the instance." ::= { ospfIfMetricEntry 3 }
ospfIfMetricMetric OBJECT-TYPE SYNTAX Metric ACCESS read-write STATUS mandatory DESCRIPTION "The metric of using this type of service on this interface. The default value of the TOS 0 Metric is 10^8 / ifSpeed.
The value FFFF is distinguished to mean 'no route via this TOS'." ::= { ospfIfMetricEntry 4 }
Baker & Coltun [Page 30]
RFC 1248 OSPF Version 2 MIB July 1991
ospfIfMetricStatus OBJECT-TYPE SYNTAX Validation ACCESS read-write STATUS mandatory DESCRIPTION "This variable displays the validity or invalidity of the entry. Setting it to 'invalid' has the effect of rendering it inoperative. The internal effect (row removal) is implementation dependent." DEFVAL { valid } ::= { ospfIfMetricEntry 5 }
-- OSPF Virtual Interface Table
-- The Virtual Interface Table describes the virtual -- links that the OSPF Process is configured to -- carry on.
ospfVirtIfTable OBJECT-TYPE SYNTAX SEQUENCE OF OspfVirtIfEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "Information about this router's virtual interfaces." REFERENCE "OSPF Version 2, Appendix C.4 Virtual link parameters" ::= { ospf 9 }
ospfVirtIfEntry OBJECT-TYPE SYNTAX OspfVirtIfEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "Information about a single Virtual Interface." INDEX { ospfVirtIfAreaID, ospfVirtIfNeighbor } ::= { ospfVirtIfTable 1 }
ospfVirtIfAreaID OBJECT-TYPE SYNTAX AreaID ACCESS read-write STATUS mandatory DESCRIPTION "The Transit Area that the Virtual Link traverses. By definition, this is not 0.0.0.0" ::= { ospfVirtIfEntry 1 }
ospfVirtIfNeighbor OBJECT-TYPE SYNTAX RouterID ACCESS read-write STATUS mandatory DESCRIPTION "The Router ID of the Virtual Neighbor." ::= { ospfVirtIfEntry 2 }
ospfVirtIfTransitDelay OBJECT-TYPE SYNTAX UpToMaxAge ACCESS read-write STATUS mandatory DESCRIPTION "The estimated number of seconds it takes to transmit a link- state update packet over this interface." DEFVAL { 1 } ::= { ospfVirtIfEntry 3 }
ospfVirtIfRetransInterval OBJECT-TYPE SYNTAX UpToMaxAge ACCESS read-write STATUS mandatory DESCRIPTION "The number of seconds between link-state advertisement retransmissions, for adjacencies belonging to this
Baker & Coltun [Page 32]
RFC 1248 OSPF Version 2 MIB July 1991
interface. This value is also used when retransmitting database description and link-state request packets. This value should be well over the expected round-trip time." DEFVAL { 5 } ::= { ospfVirtIfEntry 4 }
ospfVirtIfHelloInterval OBJECT-TYPE SYNTAX HelloRange ACCESS read-write STATUS mandatory DESCRIPTION "The length of time, in seconds, between the Hello packets that the router sends on the interface. This value must be the same for the virtual neighbor." DEFVAL { 10 } ::= { ospfVirtIfEntry 5 }
ospfVirtIfRtrDeadInterval OBJECT-TYPE SYNTAX PositiveInteger ACCESS read-write STATUS mandatory DESCRIPTION "The number of seconds that a router's Hello packets have not been seen before it's neighbors declare the router down. This should be some multiple of the Hello interval. This value must be the same for the virtual neighbor." DEFVAL { 60 } ::= { ospfVirtIfEntry 6 }
ospfVirtIfState OBJECT-TYPE SYNTAX INTEGER { down (1), -- these use the same encoding pointToPoint (4) -- as the ospfIfTable } ACCESS read-only STATUS mandatory DESCRIPTION "OSPF virtual interface states." DEFVAL { down } ::= { ospfVirtIfEntry 7 }
ospfVirtIfEvents OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION
Baker & Coltun [Page 33]
RFC 1248 OSPF Version 2 MIB July 1991
"The number of state changes or error events on this Virtual Link" DEFVAL { 0 } ::= { ospfVirtIfEntry 8 }
ospfVirtIfAuthKey OBJECT-TYPE SYNTAX OCTET STRING ACCESS read-write STATUS mandatory DESCRIPTION "If Authentication Type is simplePassword, the device will left adjust and zero fill to 8 octets.
When read, ospfVifAuthKey always returns a string of length zero." REFERENCE "OSPF Version 2, Section 9 The Interface Data Structure" DEFVAL { '0000000000000000'H } -- 0.0.0.0.0.0.0.0 ::= { ospfVirtIfEntry 9 }
ospfVirtIfStatus OBJECT-TYPE SYNTAX Validation ACCESS read-write STATUS mandatory DESCRIPTION "This variable displays the validity or invalidity of the entry. Setting it to 'invalid' has the effect of rendering it inoperative. The internal effect (row removal) is implementation dependent." DEFVAL { valid } ::= { ospfVirtIfEntry 10 }
-- OSPF Neighbor Table
-- The OSPF Neighbor Table describes all neighbors in -- the locality of the subject router.
ospfNbrTable OBJECT-TYPE SYNTAX SEQUENCE OF OspfNbrEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A table of non-virtual neighbor information." REFERENCE "OSPF Version 2, Section 10 The Neighbor Data Structure"
Baker & Coltun [Page 34]
RFC 1248 OSPF Version 2 MIB July 1991
::= { ospf 10 }
ospfNbrEntry OBJECT-TYPE SYNTAX OspfNbrEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The information regarding a single neighbor." REFERENCE "OSPF Version 2, Section 10 The Neighbor Data Structure" INDEX { ospfNbrIpAddr, ospfNbrAddressLessIndex } ::= { ospfNbrTable 1 }
ospfNbrIpAddr OBJECT-TYPE SYNTAX IpAddress ACCESS read-write STATUS mandatory DESCRIPTION "The IP address of this neighbor." ::= { ospfNbrEntry 1 }
ospfNbrAddressLessIndex OBJECT-TYPE SYNTAX InterfaceIndex ACCESS read-write STATUS mandatory
Baker & Coltun [Page 35]
RFC 1248 OSPF Version 2 MIB July 1991
DESCRIPTION " On an interface having an IP Address, zero. On addressless interfaces, the corresponding value of ifIndex in the Internet Standard MIB. On row creation, this can be derived from the instance." ::= { ospfNbrEntry 2 }
ospfNbrRtrId OBJECT-TYPE SYNTAX RouterID ACCESS read-only STATUS mandatory DESCRIPTION "A 32-bit integer (represented as a type IpAddress) uniquely identifying the neighboring router in the Autonomous System." DEFVAL { '00000000'H } -- 0.0.0.0 ::= { ospfNbrEntry 3 }
ospfNbrOptions OBJECT-TYPE SYNTAX INTEGER ACCESS read-only STATUS mandatory DESCRIPTION "A Bit Mask corresponding to the neighbor's options field.
Bit 0, if set, indicates that the area accepts and operates on external information; if zero, it is a stub area.
Bit 1, if set, indicates that the system will operate on Type of Service metrics other than TOS 0. If zero, the neighbor will ignore all metrics except the TOS 0 metric." REFERENCE "OSPF Version 2, Section 12.1.2 Options" DEFVAL { 0 } ::= { ospfNbrEntry 4 }
ospfNbrPriority OBJECT-TYPE SYNTAX DesignatedRouterPriority ACCESS read-write STATUS mandatory DESCRIPTION "The priority of this neighbor in the designated router election algorithm. The value 0 signifies that the neighbor is not eligible to become the designated router on this particular network."
Baker & Coltun [Page 36]
RFC 1248 OSPF Version 2 MIB July 1991
DEFVAL { 1 } ::= { ospfNbrEntry 5 }
ospfNbrState OBJECT-TYPE SYNTAX INTEGER { down (1), attempt (2), init (3), twoWay (4), exchangeStart (5), exchange (6), loading (7), full (8) } ACCESS read-only STATUS mandatory DESCRIPTION "The State of the relationship with this Neighbor." REFERENCE "OSPF Version 2, Section 10.1 Neighbor States" DEFVAL { down } ::= { ospfNbrEntry 6 }
ospfNbrEvents OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of times this neighbor relationship has changed state, or an error has occurred." DEFVAL { 0 } ::= { ospfNbrEntry 7 }
ospfNbrLSRetransQLen OBJECT-TYPE SYNTAX Gauge ACCESS read-only STATUS mandatory DESCRIPTION "The current length of the retransmission queue." DEFVAL { 0 } ::= { ospfNbrEntry 8 }
ospfNBMANbrStatus OBJECT-TYPE SYNTAX Validation ACCESS read-write STATUS mandatory DESCRIPTION "This variable displays the validity or invalidity of
Baker & Coltun [Page 37]
RFC 1248 OSPF Version 2 MIB July 1991
the entry. Setting it to 'invalid' has the effect of rendering it inoperative. The internal effect (row removal) is implementation dependent." DEFVAL { valid } ::= { ospfNbrEntry 9 }
-- OSPF Virtual Neighbor Table
-- This table describes all virtual neighbors. -- Since Virtual Links are configured in the -- virtual interface table, this table is read-only.
ospfVirtNbrTable OBJECT-TYPE SYNTAX SEQUENCE OF OspfVirtNbrEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A table of virtual neighbor information." REFERENCE "OSPF Version 2, Section 15 Virtual Links" ::= { ospf 11 }
ospfVirtNbrArea OBJECT-TYPE SYNTAX AreaID ACCESS read-only STATUS mandatory DESCRIPTION "The Transit Area Identifier." ::= { ospfVirtNbrEntry 1 }
ospfVirtNbrRtrId OBJECT-TYPE SYNTAX RouterID ACCESS read-only STATUS mandatory DESCRIPTION "A 32-bit integer uniquely identifying the neighboring router in the Autonomous System." ::= { ospfVirtNbrEntry 2 }
ospfVirtNbrIpAddr OBJECT-TYPE SYNTAX IpAddress ACCESS read-only STATUS mandatory DESCRIPTION "The IP address this Virtual Neighbor is using." ::= { ospfVirtNbrEntry 3 }
ospfVirtNbrOptions OBJECT-TYPE SYNTAX INTEGER ACCESS read-only STATUS mandatory DESCRIPTION "A bit map corresponding to the neighbor's options field. Thus, Bit 1, if set, indicates that the neighbor supports Type of Service Routing; if zero, no metrics other than TOS 0 are in use by the neighbor." ::= { ospfVirtNbrEntry 4 }
} ACCESS read-only STATUS mandatory DESCRIPTION "The state of the Virtual Neighbor Relationship." ::= { ospfVirtNbrEntry 5 }
ospfVirtNbrEvents OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of times this virtual link has changed its state, or an error has occurred." DEFVAL { 0 } ::= { ospfVirtNbrEntry 6 }
ospfVirtNbrLSRetransQLen OBJECT-TYPE SYNTAX Gauge ACCESS read-only STATUS mandatory DESCRIPTION "The current length of the retransmission queue." ::= { ospfVirtNbrEntry 7 }
This document was produced by the OSPF Working Group, of which the Chairman is John Moy of Proteon.
In addition, the comments of the following individuals are also acknowledged:
John Moy Proteon, Inc Dino Farinacci 3COM Stan Froyd Advanced Computer Communications Steve Willis Wellfleet John Burress Wellfleet Keith McCloghrie Hughes LAN Systems
[3] Rose M., and K. McCloghrie, "Structure and Identification of Management Information for TCP/IP-based internets", RFC 1155, Performance Systems International, Hughes LAN Systems, May 1990.
[4] McCloghrie K., and M. Rose, "Management Information Base for Network Management of TCP/IP-based internets", RFC 1156, Hughes LAN Systems, Performance Systems International, May 1990.
[5] Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple Network Management Protocol", RFC 1157, SNMP Research, Performance Systems International, Performance Systems International, MIT Laboratory for Computer Science, May 1990.
[6] Rose M., Editor, "Management Information Base for Network Management of TCP/IP-based internets: MIB-II", RFC 1213, Performance Systems International, March 1991.
[7] Information processing systems - Open Systems Interconnection - Specification of Abstract Syntax Notation One (ASN.1), International Organization for Standardization, International Standard 8824, December 1987.
[8] Information processing systems - Open Systems Interconnection - Specification of Basic Encoding Rules for Abstract Notation One (ASN.1), International Organization for Standardization, International Standard 8825, December 1987.
[9] Rose, M., and K. McCloghrie, Editors, "Concise MIB Definitions", RFC 1212, Performance Systems International, Hughes LAN Systems, March 1991.
[10] Moy, J., Editor, "The OSPF Specification, Version 2", RFC 1247, Proteon, Inc., July 1991.