3com DUA1750-2BAA01 Manual De Usuario

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 20, 30

Permit :all VLAN

Permit :VLAN 20, 40

Switch A

Switch C

Switch B

Switch D

Permit :
VLAN 10, 20

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.