The total number of L2 Port table entries,
which have been or would have been learned, but
have been discarded due to a lack of space to
store them in the Forwarding Database. If this
counter is increasing, it indicates that the
L2 port table is regularly becoming full (a
condition which has unpleasant performance effects
on the subnetwork). If this counter has a
significant value but is not presently increasing,
it indicates that the problem has been occurring
but is not persistent.