The value of the next available virtual ifIndex. This
object is used by an NMS to select an index value
for row-creation in tables indexed by ifIndex. The
current value of this object is changed to a new
value when the current value is written to an agent's
table, that is indexed by ifIndex. Row creation
using the current value of this object, allocates
a virtual ifIndex. Note the following:
1. A newly created row does not have to be active(1)
for the agent to allocate the virtual ifIndex.
2. Race conditions between multiple NMS's end when
a row is created. Rows are deemed created when
a setRequest is successfully committed (i.e.
the errorStats is noError(0)).
3. An agent that exhausts its supply of virual
ifIndex values returns zero as the value of this
object. This can be used by an NMS as an indication
to deleted unused rows and reboot the device.