OID value: 1.3.6.1.2.1.4.20.1.2
OID description:
ipAdEntIfIndex OBJECT-TYPE SYNTAX INTEGER ACCESS read-only STATUS mandatory DESCRIPTION "The index value which uniquely identifies the interface to which this entry is applicable. The interface identified by a particular value of this index is the same interface as identified by the same value of ifIndex." ::= { ipAddrEntry 2 }
See also the OID Repository website reference for 1.3.6.1.2.1.4.20.1.2