3Com Switch 7750 Configuration Guide

Root Bridge Configuration 247
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In a network that contains switches with both GVRP and MSTP employed, GVRP
packets are forwarded along the CIST. If you want to broadcast packets of a
specific VLAN through GVRP, be sure to map the VLAN to the CIST when
configuring the MSTP VLAN mapping table (The CIST of a network is the spanning
tree instance numbered 0.)
Prerequisites The status of the switches in the spanning trees are determined. That is, the status
(root, branch, or leaf) of each switch in each spanning tree instance is determined.
MST Region
Configuration
Configuration procedure
Bridge priority
configuration
Optional
The priority of a switch cannot be
changed after the switch is specified
as the root bridge or a secondary
root bridge.
“Bridge Priority
Configuration” on page 250
MSTP operation mode
configuration
Optional “MSTP Operation Mode
Configuration” on page 250
Maximum hops of MST
region configuration
Optional “MST Region Maximum Hops
Configuration” on page 251
Network diameter
configuration
Optional
The default is recommended.
“Network Diameter
Configuration” on page 252
MSTP time-related
configuration
Optional
The defaults are recommended.
“MSTP Time-related
Configuration” on page 252
Timeout time factor
configuration
Optional “Timeout Time Factor
Configuration” on page 254
Maximum transmitting
speed configuration
Optional
The default is recommended.
“Maximum Transmitting
Speed Configuration” on page
254
Edge port
configuration
Optional “Edge Port Configuration” on
page 255
Point-to-point link
related configuration
Optional “Point-to-point Link-Related
Configuration” on page 256
Table 171 Root bridge configuration
Operation Remarks Related section
Table 172 Configure an MST region
Operation Command Description
Enter system view system-view -
Enter MST region view stp region-configuration -
Configure a name for
the MST region
region-name name Required
The default MST region name of
a switch is its MAC address.
Configure the VALN
mapping table for the
MST region
instance instance-id vlan
vlan-list
Required
Both commands can be used to
configure VLAN mapping tables.
By default, all VLANs in an MST
region are mapped to spanning
tree instance 0.
vlan-mapping modulo modulo