Cisco 3110 Message Manual page 97

Chapter 2 Message and Recovery Procedures
Error Message SPANTREE-2-LOOPGUARD_BLOCK: Loop guard blocking port [chars] on
[chars].
Explanation
from the designated bridge. Because this condition could be caused by a unidirectional-link failure,
the interface is put into the blocking state and marked as loopguard-inconsistent to prevent possible
loops from being created. The first [chars] is the port name, and the second [chars] is the
spanning-tree mode displayed in the show spanning-tree privileged EXEC command.
Recommended Action
to review the list of interfaces with loopguard inconsistencies. Find out why devices connected to
the listed ports are not sending BPDUs. One reason might be that they are not running the STP. If
so, you should disable loop guard on the inconsistent interfaces by using the spanning-tree guard
none interface configuration command or by starting the STP on the remote side of the links.
Error Message SPANTREE-2-LOOPGUARD_CONFIG_CHANGE: Loop guard [chars] on port [chars]
on [chars].
Explanation
enabled, the interface is placed into the blocking state. It is marked as loopguard-inconsistent when
the message-age timer expires because no BPDUs were received from the designated bridge. This
feature is mainly used to detect unidirectional links. The first [chars] is the loopguard state (enable
or disable), the second [chars] is the interface name, and the third [chars] is the spanning-tree
instance.
Recommended Action
this is not the desired configuration; otherwise, no further action is required.
Error Message SPANTREE-2-LOOPGUARD_UNBLOCK: Loop guard unblocking port [chars] on
[chars].
Explanation
by a unidirectional link failure, the problem no longer exists. The loopguard-inconsistency is cleared
for the interface, which is taken out of the blocking state, if appropriate. The first [chars] is the port
name, and the second [chars] is the spanning-tree mode displayed in the show spanning-tree
privileged EXEC command.
Recommended Action
OL-12191-01
The spanning-tree message age timer has expired because no BPDUs were received
Enter the show spanning-tree inconsistentports privileged EXEC command
The spanning-tree loopguard configuration for the listed interface has been changed. If
Verify that this is the desired configuration for the listed interface. Correct it if
The listed interface has received a BPDU, and therefore, if the inconsistency was caused
No action is required.
Cisco Catalyst Switch Module 3110 and 3012 for IBM BladeCenter System Message Guide
SPANTREE Messages
2-81