Consider how the ipNetToMediaTable from MIB-II might be fully described:
-- the IP Address Translation tables -- The Address Translation tables contain IpAddress to -- "physical" address equivalences. Some interfaces do not -- use translation tables for determining address equivalences -- (e.g., DDN-X.25 has an algorithmic method); if all -- interfaces are of this type, then the Address Translation -- table is empty, i.e., has zero entries. ipNetToMediaTable OBJECT-TYPE SYNTAX SEQUENCE OF IpNetToMediaEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The IP Address Translation table used for mapping from IP addresses to physical addresses." ::= { ip 22 } ipNetToMediaEntry OBJECT-TYPE SYNTAX IpNetToMediaEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "Each entry contains one IpAddress to 'physical' address equivalence." INDEX { ipNetToMediaIfIndex, ipNetToMediaNetAddress } ::= { ipNetToMediaTable 1 } IpNetToMediaEntry ::= SEQUENCE { ipNetToMediaIfIndex INTEGER, ipNetToMediaPhysAddress OCTET STRING, ipNetToMediaNetAddress IpAddress, ipNetoToMediaType INTEGER } ipNetToMediaIfIndex OBJECT-TYPE SYNTAX INTEGER ACCESS read-write STATUS mandatory DESCRIPTION "The interface on which this entry's equivalence is effective. The interface identified by a particular value of this index is the same interface as identified by the same value of ifIndex." ::= { ipNetToMediaEntry 1 } ipNetToMediaPhysAddress OBJECT-TYPE SYNTAX OCTET STRING ACCESS read-write STATUS mandatory DESCRIPTION "The media-dependent 'physical' address." ::= { ipNetToMediaEntry 2 } ipNetToMediaNetAddress OBJECT-TYPE SYNTAX IpAddress ACCESS read-write STATUS mandatory DESCRIPTION "The IpAddress corresponding to the media- dependent 'physical' address." ::= { ipNetToMediaEntry 3 } ipNetToMediaType OBJECT-TYPE SYNTAX INTEGER { other(1), -- none of the following invalid(2), -- an invalidated mapping dynamic(3), static(4) } ACCESS read-write STATUS mandatory DESCRIPTION "The type of mapping. Setting this object to the value invalid(2) has the effect of invalidating the corresponding entry in the ipNetToMediaTable. That is, it effectively disassociates the interface identified with said entry from the mapping identified with said entry. It is an implementation-specific matter as to whether the agent removes an invalidated entry from the table. Accordingly, management stations must be prepared to receive tabular information from agents that corresponds to entries not currently in use. Proper interpretation of such entries requires examination of the relevant ipNetToMediaType object." ::= { ipNetToMediaEntry 4 }