3com 4210 PWR 9-Port 3CR17341-91-ME User Manual

Product codes
3CR17341-91-ME
Page of 567
Configuring Guard Functions
173
Perform the mCheck operation in system view
Perform the mCheck operation in Ethernet port view
Configuration Example
# Perform the mCheck operation on Ethernet 1/0/1.
Perform this configuration in system view
<4210> system-view
 
[4210] stp interface Ethernet1/0/1 mcheck 
Perform this configuration in Ethernet port view
<4210> system-view
 
[4210] interface Ethernet1/0/1
 
[4210-Ethernet1/0/1] stp mcheck 
Configuring Guard 
Functions
Introduction
The following guard functions are available on an MSTP-enabled switch: BPDU 
guard, root guard, loop guard, TC-BPDU attack guard, and BPDU drop.
BPDU guard
Normally, the access ports of the devices operating on the access layer are directly 
connected to terminals (such as PCs) or file servers. These ports are usually 
configured as edge ports to achieve rapid transition. But they resume non-edge 
ports automatically upon receiving configuration BPDUs, which causes spanning 
tree recalculation and network topology jitter.
Normally, no configuration BPDU will reach edge ports. But malicious users can 
attack a network by sending configuration BPDUs deliberately to edge ports to 
cause network jitter. You can prevent this type of attacks by utilizing the BPDU 
guard function. With this function enabled on a switch, the switch shuts down the 
edge ports that receive configuration BPDUs and then reports these cases to the 
administrator. Ports shut down in this way can only be restored by the 
administrator.
Table 128   Perform the mCheck operation in system view
Operation 
Command 
Description 
Enter system view 
system-view 
Perform the mCheck 
operation 
stp [ interface interface-list ] 
mcheck 
Required
Table 129   Perform the mCheck operation in Ethernet port view
Operation 
Command 
Description 
Enter system view 
system-view 
Enter Ethernet port view 
interface interface-type 
interface-number
 
Perform the mCheck 
operation 
stp mcheck 
Required