3Com Switch 8800 Configuration Guide Chapter 38 MSTP Region-configuration
38-36
Operation Command
Enable STP global error or event
debugging debugging stp { global-error |
global-event }
Disable STP global error or event
debugging undo debugging stp { global-error |
global-event }
38.4 Typical MSTP Configuration Example
I. Network requirements
MSTP provides different forwarding paths for packets of different VLANs. The
configurations are as follows: all the switches in the network belong to the same MST
domain, packets of VLAN 10 travels along instance 1, packets of VLAN 30 travels along
instance 3, packets of VLAN 40 travels along instance 4, and that of VLAN 20 travels
along instance 0.
In the following network diagram, Switch A and Switch B are devices of the
convergence layer, Switch C and Switch D are devices of the access layer. VLAN 10
and 30 function at the distribution and access layers, and VLAN 40 functions at the
access layer only. So the root of instance 1 can be configured as Switch A, root of
instance 3 can be Switch B, and root of instance 4 can be Switch C.
II. Network diagram
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
Figure 38-9 Network diagram for MSTP configuration
Note:
The explanations on the above figure which goes like “permit: XXXX” means that
packets of these VLANs are permitted to pass.