Indicates the reason why this port has been placed in a
non-forwarding state on this MSTI (other than as a result
of normal Spanning Tree protocol operation).
none(1) - the port has not been placed in a non-forwarding
state due to any exceptional condition.
disputed(2) - the port has been placed in listening state
because it has a designated role and an
inferior designated BPDU has been received.
spanGuardLocked(3) - the port has been placed in blocking
state because it is configured as an
admin edge port and a BPDU has been
received.
loopProtectEvent(4) - the port has been placed in listening
or blocking state because a BPDU
timeout has occurred and the port is
awaiting reception of a type 2 BPDU
on a point-to-point link.
loopProtectAdvisory(5) - the port has been placed in
listening state because a BPDU
timeout has occurred (as with a
Loop Protect event), but this
condition may be normal because
the link partner does not support
the Loop Protect feature.
loopbackDetected(6) - the port has been placed in blocking
state because a loopback condition
has been detected.