3com 3.01.01 User Manual

After configured with BPDU protection, the switch will disable the edge port 
through MSTP, which receives a BPDU, and notifies the network manager at the 
same time. These ports can be resumed by the network manager only. 

The port configured with root protection only plays the role of designated port on 
every instance. Whenever such a port receives a higher-priority BPDU, that is, it is 
about to turn into non-designated port, it will be set to listening state and will not 
forward packets any more (as if the link to the port is disconnected). If the port has 
not received any higher-priority BPDU for a certain period of time thereafter, it will 
resume the normal state. 

When you configure a port, only one configuration at a time can be effective 
among loop protection, root protection, and edge port configuration.

By default, the switch does not enable BPDU protection, root protection, or edge 
port protection. 

For more about the configuration commands, see the Switch 8800 Command 
Reference Guide.

You can use the following command to enable MSTP on the device. 

Perform the following configuration in system view. 

Only if MSTP has been enabled on the device will other MSTP configurations take 
effect. 

By default, MSTP is disabled. 

You can use the following command to enable or disable MSTP on a port. You 
may disable MSTP on some Ethernet ports of a switch to spare them from 
spanning tree calculation. This measure flexibly controls MSTP operation and saves 
the CPU resources of the switch. 

MSTP can be enabled/disabled on a port the following ways. 

Configure switch loop protection function 
(from Ethernet port view)

Restore the disabled loop protection state, as 
defaulted (from Ethernet port view)

Table 22   Configure the Switch Security Function

Table 23   Enable/Disable MSTP on a Device

Enable MSTP on a device.

Disable MSTP on a device.

Restore the disable state of MSTP, as 
defaulted.