3Com Switch 7750 Configuration Guide

266 CHAPTER 30: MSTP CONFIGURATION
MAC address tables frequently and negative effects to STP calculation and
network stability.
You can use the stp tc-protection threshold command to set a threshold for the
times of removing MAC address tables in a period. If the number of received
TC-BPDUs is less than the specified upper threshold, the switch removes its MAC
address table upon receiving a TC-BPDU. If the number of received TC-BPDUs is
more than the specified upper threshold, the switch will remove its MAC address
table for the times equal to the specified upper threshold. For example, if you set
the upper threshold for the times for the switch to remove its MAC address table
to 100 in the specific period, while the switch receives 200 TC-BPDUs in the
period. In this case, the switch removes its MAC address table for only 100 times
within the period.
c
CAUTION: Among loop guard function, root protection function, and edge port
setting, only one can be valid on a port at one time.
BPDU Protection
Configuration
Configuration prerequisites
MSTP is enabled on the current switch.
Configuration procedure
Configuration example
# Enable the BPDU guard function.
<SW7750> system-view
[SW7750] stp bpdu-protection
c
CAUTION: As Gigabit ports of a Switch 7750 cannot be shut down, the BPDU
guard function is not applicable to these ports even if you enable the BPDU guard
function and specify these ports to be MSTP edge ports.
Root Guard
Configuration
Configuration prerequisites
MSTP is enabled on the current switch.
Configuration procedure
Table 198 Enable the BPDU guard function
Operation Command Description
Enter system view system-view -
Enable the BPDU
guard function
stp bpdu-protection Required
The BPDU guard function is
disabled by default.
Table 199 Enable the root guard function in system view
Operation Command Description
Enter system view system-view -
Enable the root guard
function on specified
ports
stp interface interface-list
root-protection
Required
The root guard function is
disabled by default.