3.4. OSPF Link State Database

--  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
        MAX-ACCESS   not-accessible
        STATUS   current
        DESCRIPTION
           "The OSPF Process's Link State Database."
       REFERENCE
          "OSPF Version 2, Section 12  Link  State  Adver-
          tisements"
      ::= { ospf 4 }


    ospfLsdbEntry OBJECT-TYPE
        SYNTAX   OspfLsdbEntry
        MAX-ACCESS   not-accessible
        STATUS   current
        DESCRIPTION
           "A single Link State Advertisement."
       INDEX { ospfLsdbAreaId, ospfLsdbType,
               ospfLsdbLsid, ospfLsdbRouterId }
       ::= { ospfLsdbTable 1 }

OspfLsdbEntry ::=
    SEQUENCE {
        ospfLsdbAreaId
            AreaID,
        ospfLsdbType
            INTEGER,
        ospfLsdbLsid
            IpAddress,
        ospfLsdbRouterId
            RouterID,
        ospfLsdbSequence
            Integer32,
        ospfLsdbAge
            Integer32,
        ospfLsdbChecksum
            Integer32,
        ospfLsdbAdvertisement
            OCTET STRING
              }
    ospfLsdbAreaId OBJECT-TYPE
        SYNTAX   AreaID
        MAX-ACCESS   read-only
        STATUS   current
        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 }

-- External Link State Advertisements are permitted
-- for backward compatibility, but should be displayed in
-- the ospfExtLsdbTable rather than here.

    ospfLsdbType OBJECT-TYPE
        SYNTAX   INTEGER    {
                    routerLink (1),
                    networkLink (2),
                    summaryLink (3),
                    asSummaryLink (4),
                    asExternalLink (5), -- but see ospfExtLsdbTable
                    multicastLink (6),
                    nssaExternalLink (7)
                  }
        MAX-ACCESS   read-only
        STATUS   current
        DESCRIPTION
           "The type  of  the  link  state  advertisement.
           Each  link state type has a separate advertise-
           ment format."
       REFERENCE
          "OSPF Version 2, Appendix A.4.1 The  Link  State
          Advertisement header"
      ::= { ospfLsdbEntry 2 }

    ospfLsdbLsid OBJECT-TYPE
        SYNTAX   IpAddress
        MAX-ACCESS   read-only
        STATUS   current
        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 }
    ospfLsdbRouterId OBJECT-TYPE
        SYNTAX   RouterID
        MAX-ACCESS   read-only
        STATUS   current
        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   Integer32
        MAX-ACCESS   read-only
        STATUS   current
        DESCRIPTION
           "The sequence number field is a  signed  32-bit
           integer.   It  is used to detect old and dupli-
           cate 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   Integer32    -- Should be 0..MaxAge
        MAX-ACCESS   read-only
        STATUS   current
        DESCRIPTION
           "This field is the age of the link state adver-
           tisement in seconds."
       REFERENCE
          "OSPF Version 2, Section 12.1.1 LS age"
      ::= { ospfLsdbEntry 6 }

    ospfLsdbChecksum OBJECT-TYPE
        SYNTAX   Integer32
        MAX-ACCESS   read-only
        STATUS   current
        DESCRIPTION
           "This field is the  checksum  of  the  complete
           contents  of  the  advertisement, excepting the
           age field.  The age 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 connec-
           tionless 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 (SIZE (1..65535))
        MAX-ACCESS   read-only
        STATUS   current
        DESCRIPTION
           "The entire Link State Advertisement, including
           its header."
       REFERENCE
          "OSPF Version 2, Section 12  Link  State  Adver-
          tisements"
      ::= { ospfLsdbEntry 8 }