2.6. The MIB View Database Group

   -- the MIB view database group

   snmpViews      OBJECT IDENTIFIER ::= { partyMIBObjects 4 }

   viewTable OBJECT-TYPE
       SYNTAX      SEQUENCE OF ViewEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
               "Locally held information about the MIB views
               known to this SNMPv2 entity.

               Each SNMPv2 context which is locally accessible
               has a single MIB view which is defined by two
               collections of view subtrees: the included view
               subtrees, and the excluded view subtrees.  Every
               such subtree, both included and excluded, is
               defined in this table.

               To determine if a particular object instance is in
               a particular MIB view, compare the object
               instance's OBJECT IDENTIFIER with each of the MIB
               view's entries in this table.  If none match, then
               the object instance is not in the MIB view.  If
               one or more match, then the object instance is
               included in, or excluded from, the MIB view
               according to the value of viewType in the entry
               whose value of viewSubtree has the most sub-
               identifiers.  If multiple entries match and have
               the same number of sub-identifiers, then the
               lexicographically greatest instance of viewType
               determines the inclusion or exclusion.

               An object instance's OBJECT IDENTIFIER X matches
               an entry in this table when the number of sub-
               identifiers in X is at least as many as in the
               value of viewSubtree for the entry, and each sub-
               identifier in the value of viewSubtree matches its
               corresponding sub-identifier in X.  Two sub-
               identifiers match either if the corresponding bit
               of viewMask is zero (the 'wild card' value), or if
               they are equal.

               Due to this 'wild card' capability, we introduce
               the term, a 'family' of view subtrees, to refer to
               the set of subtrees defined by a particular
               combination of values of viewSubtree and viewMask.
               In the case where no 'wild card' is defined in
               viewMask, the family of view subtrees reduces to a
               single view subtree."
       ::= { snmpViews 1 }

   viewEntry OBJECT-TYPE
       SYNTAX      ViewEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
               "Information on a particular family of view
               subtrees included in or excluded from a particular
               SNMPv2 context's MIB view.

               Implementations must not restrict the number of
               families of view subtrees for a given MIB view,
               except as dictated by resource constraints on the
               overall number of entries in the viewTable."
       INDEX      { viewIndex, IMPLIED viewSubtree }
       ::= { viewTable 1 }

   ViewEntry ::=
       SEQUENCE {
           viewIndex        INTEGER,
           viewSubtree      OBJECT IDENTIFIER,
           viewMask         OCTET STRING,
           viewType         INTEGER,
           viewStorageType  StorageType,
           viewStatus       RowStatus
       }

   viewIndex OBJECT-TYPE
       SYNTAX      INTEGER (1..65535)
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
               "A unique value for each MIB view.  The value for
               each MIB view must remain constant at least from
               one re-initialization of the entity's network
               management system to the next re-initialization."
       ::= { viewEntry 1 }

   viewSubtree OBJECT-TYPE
       SYNTAX      OBJECT IDENTIFIER
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
               "A MIB subtree."
       ::= { viewEntry 2 }

   viewMask OBJECT-TYPE
       SYNTAX      OCTET STRING (SIZE (0..16))
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
               "The bit mask which, in combination with the
               corresponding instance of viewSubtree, defines a
               family of view subtrees.

               Each bit of this bit mask corresponds to a sub-
               identifier of viewSubtree, with the most
               significant bit of the i-th octet of this octet
               string value (extended if necessary, see below)
               corresponding to the (8*i - 7)-th sub-identifier,
               and the least significant bit of the i-th octet of
               this octet string corresponding to the (8*i)-th
               sub-identifier, where i is in the range 1 through
               16.

               Each bit of this bit mask specifies whether or not
               the corresponding sub-identifiers must match when
               determining if an OBJECT IDENTIFIER is in this
               family of view subtrees; a '1' indicates that an
               exact match must occur; a '0' indicates 'wild
               card', i.e., any sub-identifier value matches.

               Thus, the OBJECT IDENTIFIER X of an object
               instance is contained in a family of view subtrees
               if the following criteria are met:

                    for each sub-identifier of the value of
                    viewSubtree, either:

                         the i-th bit of viewMask is 0, or

                         the i-th sub-identifier of X is equal to
                         the i-th sub-identifier of the value of
                         viewSubtree.

               If the value of this bit mask is M bits long and
               there are more than M sub-identifiers in the
               corresponding instance of viewSubtree, then the
               bit mask is extended with 1's to be the required
               length.

               Note that when the value of this object is the
               zero-length string, this extension rule results in
               a mask of all-1's being used (i.e., no 'wild
               card'), and the family of view subtrees is the one
               view subtree uniquely identified by the
               corresponding instance of viewSubtree."
       DEFVAL      { ''H }
       ::= { viewEntry 3 }

   viewType OBJECT-TYPE
       SYNTAX      INTEGER  {
                       included(1),
                       excluded(2)
                   }
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
               "The status of a particular family of view
               subtrees within the particular SNMPv2 context's
               MIB view.  The value 'included(1)' indicates that
               the corresponding instances of viewSubtree and
               viewMask define a family of view subtrees included
               in the MIB view.  The  value 'excluded(2)'
               indicates that the corresponding instances of
               viewSubtree and viewMask define a family of view
               subtrees excluded from the MIB view."
       DEFVAL      { included }
       ::= { viewEntry 4 }

   viewStorageType OBJECT-TYPE
       SYNTAX      StorageType
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
               "The storage type for this conceptual row in the
               viewTable."
       DEFVAL      { nonVolatile }
       ::= { viewEntry 5 }

   viewStatus OBJECT-TYPE
       SYNTAX      RowStatus
       MAX-ACCESS  read-create
       STATUS      current
       DESCRIPTION
               "The status of this conceptual row in the
               viewTable."
       ::= { viewEntry 6 }