Chapter 4. Web Configuration & Operation
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CHAPTER 3
WEB OPERATION & CONFIGURATION
Maximum Hop Count:
The maximum number of hops allowed for MST region before a BPDU is discarded. Each bridge
decrements the hop count by one before passing on the BPDU. When the hop count reaches zero, the BPDU is
discarded. The default hop count is 20. The allowed range is 6-40.
Transmit Hold Count:
The number of BPDU sent by a bridge port per second. When exceeded, transmission of the
next BPDU will be delayed. By default, it is set to 6. The allowed transmit hold count is 1 to 10. Please note that
increasing this value might have a significant impact on CPU utilization and decreasing this value might slow down
convergence. It is recommended to remain Transmit Hold Count to the default setting.
Advanced Settings
Edge Port BPDU Filtering:
The purpose of Port BPDU Filtering is to prevent the switch from sending BPDU frames on
ports that are connected to end devices.
Edge Port BPDU Guard:
Edge ports generally connect directly to PC, file servers or printers. Therefore, edge ports are
configured to allow rapid transition. Under normal situations, edge ports should not receive configuration BPDUs.
However, if they do, this probably is due to malicious attacks or mis-settings. When edge ports receive configuration
BPDUs, they will be automatically set to non-edge ports and start a new spanning tree calculation process.
BPDU Guard is therefore used to prevent the device from suffering malicious attacks. With this function enabled,
when edge ports receive configuration BPDUs, STP disables those affected edge ports. After a period of recovery time,
those disabled ports are re-activated.
Port Error Recovery:
When enabled, a port that is in the error-disabled state can automatically be enabled after a
certain time.
Port Error Recovery Timeout:
The time that has to pass before a port in the error-disabled state can be enabled. The
allowed range is 30 – 86400 seconds.
