MSTP/1/TOPOC:OID [OID] Bridge topology change.
The topology calculated by the STP changes.
A topologyChange alarm is triggered if the status of an STP interface other than an edge interface changes from Blocking to Forwarding.
1. The network topology changes because a new link is added into the network topology.
2. The network topology changes because interfaces go Up or Down.
3. The network topology changes because a device changed the priority.
4. The network topology changes because a device changed the priority, or an interface changed its priority or cost, which caused a change in the blocked interface.
If so, go to Step 2.
If not, go to Step 4.
If so, go to Step 3.
If not, go to Step 8.
If so, go to Step 10.
If not, go to Step 4.
If so, go to Step 5.
If not, go to Step 6.
If so, go to Step 10.
If not, go to Step 6.
If so, go to Step 7.
If not, go to Step 9.
If the alarm is cleared, go to Step 10.
If the alarm is not cleared, go to Step 9.
If the alarm is cleared, go to Step 10.
If the alarm is not cleared, go to Step 3.