Failures Occurring When The Spanning Tree Functionality Is Used - Alaxala AX6700S Troubleshooting Manual

3 Troubleshooting Functional Failures During Operation
1. The MAC address learning limit value has been reached, and MAC address learning
has been stopped. Received frames that contain an unlearned sender MAC address
are discarded without the MAC address being learned. However, frames from a
VLAN for which MAC address learning is suppressed are flooded.
2. MAC address learning is set to be suppressed. The received frames are flooded.
(4) Checking filtering and QoS control
Certain packets might have been discarded either by filtering or by bandwidth monitoring,
drop control, or the QoS control shaper. Make sure that the setting conditions for filtering
and QoS control in the configuration are correct, and that bandwidth monitoring, drop
control, or the shaper is used appropriately in the system configuration. For details about
the procedure, see 3.24.1 Checking the filtering and QoS control configuration information.

3.5.2 Failures occurring when the spanning tree functionality is used

If Layer 2 communication fails or the operating status of the spanning tree does not
conform to the network configuration when the spanning tree functionality is used, use the
analysis method described below to isolate the cause of the problem. For multiple spanning
trees, perform the check for each CIST or each MST instance. When checking a route
bridge, for example, replace the word route bridge with CIST route bridge or route bridge
for each MST instance.
Table 3-14 Failure analysis method for spanning trees
No. Items to check and commands
1 Execute the
show
spanning-tree
spanning tree that caused the
failure, and then check the status of
the protocol for the spanning tree.
2 Execute the
show
spanning-tree
spanning tree that caused the
failure, and then check the bridge
identifier of the route bridge for the
spanning tree.
54
Action
If the displayed status is Enable, go to No. 2.
command for the
If Ring Protocol and PVST+ are used together, but the tree
information of the target VLAN is not displayed, go to No. 7.
If the displayed status is Disable, the spanning tree has stopped.
Check the configuration.
If Ring Protocol and multiple spanning trees are used together, go
to No. 8.
Check whether the number of the PVST+ instances is within the
device capacities.
If the bridge identifier of the route bridge indicates the route bridge
command for the defined in the network configuration, go to No. 3.
If the bridge identifier of the route bridge does not indicate the
route bridge defined in the network configuration, check the
network configuration and other configurations.