An integer whose value represents a bitstring. These
bit values indicate flag settings for this interface
as well as status information. Note that the MIB-II
interface group also contains status information, but
this is relative to IP (if IP is not enabled on the card,
it is marked as down). The value is determined by
summing the following:
1 - Heartbeat
2 - Primary
4 - Active
8 - HW Failure Detected
16 - Connectivity Failure Detected