Cisco Catalyst 2000 Configuration Handbook page 144

1/1
Fwd: VLAN 100 (cost 19)
Block: VLAN 101 (cost 1000)
Root
Bridge
Catalyst D1
Catalyst A1
Catalyst D2
Catalyst D1
STP Topology
VLAN 100
Figure 7-3 Network Diagram for the STP Load-Balancing Example
Catalyst D1 can be configured with these commands:
(global) spanning-tree vlan 100 root primary
(global) spanning-tree vlan 101 root primary
Alternatively, you can explicitly set the bridge priorities with these commands (available
on all Catalyst models):
(global) spanning-tree vlan 100 priority 8192
(global) spanning-tree vlan 101 priority 8192
Catalyst D2 can be configured with these commands to become the secondary root:
(global) spanning-tree vlan 100 root secondary
(global) spanning-tree vlan 101 root secondary
Alternatively, you can explicitly set D2's bridge priorities:
(global) spanning-tree vlan 100 priority 8200
(global) spanning-tree vlan 101 priority 8200
Chapter 7: Spanning Tree Protocol (STP) 123
Catalyst A1
Block: VLAN 100 (cost 1000)
Fwd: VLAN 101 (cost 19)
19
19
19
Catalyst D2
Catalyst D1
1/2
Catalyst A1
Catalyst D2
STP Topology
VLAN 101