Subtyping Properties in the OBJECT-TYPE INDEX Clause

[This is preliminary documentation and subject to change.]

When an SNMP table collection contains an INDEX clause that contains an SNMP supported type that, in turn, contains a subtype definition derived from a fixed-length OCTET STRING, then the property must also define a further qualifier which specifies that fixed-length value. The CIM property qualifier fixed_length specifies this value.

The following example is an excerpt from the bridge-forwarding table:

MacAddress ::= OCTET STRING (SIZE (6))

dot1dTpFdbTable OBJECT-TYPE
       SYNTAX  SEQUENCE OF Dot1dTpFdbEntry
       ACCESS  not-accessible
       STATUS  mandatory
       DESCRIPTION
               "A table that contains information about unicast
               entries for which the bridge has forwarding and/or
               filtering information.  This information is used
               by the transparent bridging function in
               determining how to propagate a received frame."
       ::= { dot1dTp 3 }

dot1dTpFdbEntry OBJECT-TYPE
       SYNTAX  Dot1dTpFdbEntry
       ACCESS  not-accessible
       STATUS  mandatory
       DESCRIPTION
               "Information about a specific unicast MAC address
               for which the bridge has some forwarding and/or
               filtering information."
       INDEX   { dot1dTpFdbAddress }
       ::= { dot1dTpFdbTable 1 }

   Dot1dTpFdbEntry ::=
       SEQUENCE {
           dot1dTpFdbAddress
               MacAddress,
           dot1dTpFdbPort
               INTEGER,
           dot1dTpFdbStatus
               INTEGER
       }

   dot1dTpFdbAddress OBJECT-TYPE
       SYNTAX  MacAddress
       ACCESS  read-only
       STATUS  mandatory
       DESCRIPTION
               "A unicast MAC address for which the bridge has
               forwarding and/or filtering information."
       REFERENCE
               "P802.1d/D9, July 14, 1989: Section 3.9.1, 3.9.2"
       ::= { dot1dTpFdbEntry 1 }

This example maps to the following CIM class definition:

[
        description ( 

            "A table that contains information about unicast
            entries for which the bridge has forwarding and/or
            filtering information.  This information is used
            by the transparent bridging function in
            determining how to propagate a received frame.

            Information about a specific unicast MAC address
          for which the bridge has some forwarding and/or
            filtering information."
        ) ,
        module_name ("RFC1286-MIB"),
        group_objectid ("1.3.6.1.2.1.17")
    ]
    class SNMP_RFC1286_MIB_Dot1dTpFdbTable
    {
        [   read,key,key_order(1),
            fixed_length(6),
            object_syntax("MacAddress"),
            textual_convention("MacAddress"),
            encoding("OCTETSTRING"),
            object_identifier("1.3.6.1"),
            description ( 

            "A unicast MAC address for which the bridge has
           forwarding and/or filtering information."
            )
        ]
        string dot1dTpFdbAddress;
    }