3com 8807 Reference Guide

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C
HAPTER
 13: MSTP C
ONFIGURATION
 C
OMMANDS
This configuration takes effect on the CIST and all the MSTIs. The settings of a port 
whether to connect the point-to-point link will be applied to all the MSTIs where 
the port belongs. Note that a temporary loop may be redistributed if you configure 
a port not physically connected with the point-to-point link as connected to such a 
link by force.
Related command: stp point-to-point.
Example
# Configure Ethernet2/1/3 to be connected to the point-to-point link.
<SW8800>system-view
 
System View: return to User View with Ctrl+Z.
 
[SW8800] stp interface Ethernet2/1/3 point-to-point force-true 
stp interface 
root-protection
Syntax
stp interface interface-list root-protection
undo stp interface interface-list root-protection
View
System view
Parameter
interface-list: Ethernet port list, containing multiple Ethernet ports and expressed 
as interface-list = { interface-type interface-number [ to interface-type 
interface-number
 ] }&<1-10>. For detail descriptions of interface-type and 
interface-number parameters, refer to the corresponding descriptions in Port 
Command Manual
. &<1-10> means that the preceding parameters can be 
entered up to 10 times.
Description
Use the stp interface root-protection command to enable Root protection on 
the switch in system view.
Use the undo stp interface root-protection command to restore the default 
Root protection state.
By default, Root protection is disabled.
In case of configuration error or malicious attack, the legal primary root may 
receive the BPDU with a higher priority and then loose its place, which causes 
network topology change errors. Due to the illegal change, the traffic supposed to 
travel over the high-speed link may be pulled to the low-speed link and congestion 
will occur on the network.
Root protection function is used against such problem. The port configured with 
Root protection only plays a role of designated port on every instance. Whenever 
such 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 not forward packets any 
more (as if the link to the port is disconnected). So, Root protection takes effect 
only when it is enabled on a designated port. If the port has not received any