OID value: 1.3.6.1.2.1.4.21.1.2
OID description:
ipRouteIfIndex OBJECT-TYPE
SYNTAX INTEGER
ACCESS read-write
STATUS mandatory
DESCRIPTION
"The index value which uniquely identifies the
local interface through which the next hop of this
route should be reached. The interface identified
by a particular value of this index is the same
interface as identified by the same value of
ifIndex."
::= { ipRouteEntry 2 }
See also the OID Repository website reference for 1.3.6.1.2.1.4.21.1.2