Description: This value indicates the number of bits in a VLAN Id
that are considered significant in the forwarding decision
of a packet.  This allows VLANs to be grouped together into
logical units.  Within the scope of these VLAN groups, unicast
traffic may be bridged between VLANs, but, multicast and broadcast
traffic is scoped to a specific VLAN.

In the following depiction M represents the number of
significant bits as specified by a set of the object.
An X in a box represents that the bit is considered
significant based on the value of M.

       11  10  9   8   7   6   5   4  3    2   1   0
     +===============================================+
M=0  |   |   |   |   |   |   |   |   |   |   |   |   |
     +===============================================+

       11  10  9   8   7   6   5   4  3    2   1   0
     +===============================================+
M=4  |   |   |   |   |   |   |   |   | X | X | X | X |
     +===============================================+

       11  10  9   8   7   6   5   4  3    2   1   0
     +===============================================+
M=9  |   |   |   | X | X | X | X | X | X | X | X | X |
     +===============================================+


Significant bits are assigned sequentially starting with bit
zero and ending with bit M-1.

For a set value of M, (2 ^ M) VLAN groups will be created.  Each
group will contain (2 ^ (12 - M)) VLAN Ids, with the exception
of the first group and last group which will each have
((2 ^ (12 - M)) - 1) VLAN Ids (VLAN Ids 0 and 4095 are reserved).
VLAN groups are numbered sequentially from 0 through ((2 ^ M) - 1).
The VLAN Ids assigned to each group, N, are assigned sequentially
starting with (N * (2 ^ (12 - M))) through
((N * (2 ^ (12 - M))) + ((2 ^ (12 - M)) - 1)), with the exception
of group zero which always starts with VLAN Id 1 and group
((2 ^ M) -1) which always ends with VLAN Id 4094.

The number of bits specified allows the maximum amount of
flexibility in the scoping of traffic, without compromising
security between VLANS.  For example, a set value of 0 would
create a single VLAN group with 4094 VLAN Ids.  This configuration
would allow all unicast traffic to be bridged between VLANS,
while scoping all multicast and broadcast traffic to a specific VLAN.
A set value of 12 would restrict all unicast, multicast and broadcast
traffic to a specific VLAN.  In this configuration no traffic
would be bridged between VLANS.

Setting of this object is limited to devices which support
configurable(2) operational modes as specified by
ctVlanSupportedOperationalMode.  A set of this object for a
device which only supports static(1) operational mode will fail.
A read of this object for a device that only supports
static(1) operational mode will always return 12.