3Com Switch 4200G Configuration Guide

MSTP Displaying and Debugging 145
MSTP Displaying and
Debugging
You can verify the above configurations by executing the display commands in any
view.
Execute the reset command in user view to clear MSTP statistics. Execute the
debugging command in user view to debug the MSTP module.
MSTP Implementation
Example
Network requirements
Implement MSTP in the network shown in Figure 42 to enable packets of different
VLANs to be forwarded along different spanning tree instances. The detailed
configurations are as follows:
■ All switches in the network belong to the same MST region.
■ Packets of VLAN 10, VLAN 30, VLAN 40, and VLAN 20 are forwarded along
spanning tree instance 1, instance 3, instance 4, and instance 0 respectively.
In this network, Switch A and Switch B operate on the distribution layer; Switch C
and Switch D operate on the access layer. VLAN 10 and VLAN 30 are limited in the
distribution layer and VLAN 40 is limited in the access layer. Switch A and Switch B are
configured as the root bridges of spanning tree instance 1 and spanning tree instance
3 respectively. Switch C is configured as the root bridge of spanning tree instance 4.
Network diagram
Figure 42 Network diagram for implementing MSTP
The Permit: shown in Figure 42 means the corresponding link permits packets of
specific VLANs.
Configuration procedure
1 Configure Switch A.
a Enter MST region view.
<S4200G> system-view
System View: return to User View with Ctrl+Z.
[4200G] stp region-configuration
Table 121 Display and debug MSTP
Operation Command
Display spanning tree-related information
about the current switch
display stp [ instance instance-id ] [
interface interface-list | slot slot-number ] [
brief ]
Display region configuration display stp region-configuration
Clear MSTP-related statistics reset stp [ interface interface-list ]
Switch A
Switch C
Switch B
Switch D
Permit :
VLAN 10, 20
Permit :
VLAN 10, 20
Permit :
VLAN 20, 30
Permit :
VLAN 20, 30
Permit :all VLAN
Permit :VLAN 20, 40
Switch A
Switch C
Switch B
Switch D
Permit :
VLAN 10, 20
Permit :
VLAN 10, 20
Permit :
VLAN 20, 30
Permit :
VLAN 20, 30
Permit :all VLAN
Permit :VLAN 20, 40