The number of input packets which were simply
ignored by this physical interface due to
insufficient resources to handle the incoming
packets.
For example, this could indicate that the input
receive buffers are not available or that the
receiver lost a packet.
Discontinuities in the value of this variable
can occur at re-initialization of the
management system, and at other times as
indicated by the values of
cieIfPacketDiscontinuityTime.