The interface index (value of ifIndex) that this action occurs on. This may be derived from the diffServDataPathStartEntry's index by extension through the various RowPointers. However, as this may be difficult for a network management station, it is placed here as well. If this is indeterminate, the value is zero.

This is of especial relevance when reporting the counters which may apply to traffic crossing an interface: diffServCountActOctets, diffServCountActPkts, diffServAlgDropOctets, diffServAlgDropPkts, diffServAlgRandomDropOctets, and diffServAlgRandomDropPkts.

It is also especially relevant to the queue and scheduler which may be subsequently applied.