A list of all the interface entries in the system which
are registered with IP.
This table contains objects which are applicable for the
management of IP over the network interfaces
in the system.
This table is a extension to the ifMainTable.
The index to this table has the semantics of
the ifMainIndex of the ifMainTable.
Entries are created automatically in this table for
any interface sub-layer which is layer below IP using
the ifStackTable. Similarly, entries are deleted from
this table when the interface's layering below IP is
removed.