Cisco Catalyst 2000 User Manual

Chapter 7: Spanning Tree Protocol (STP) 123
Section 7-2
1/1
Fwd: VLAN 100 (cost 19)
Block: VLAN 101 (cost 1000)
1/2
Block: VLAN 100 (cost 1000)
Fwd: VLAN 101 (cost 19)
Catalyst A1
Catalyst D1 Catalyst D2
19
19
19
Root
Bridge
Catalyst A1
Catalyst D1
Catalyst D2
Catalyst A1
Catalyst D1
Catalyst D2
STP Topology
VLAN 100
STP Topology
VLAN 101
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

Cisco Catalyst 2000 Specifications

General

Brand	Cisco
Model	Catalyst 2000
Category	Switch
Language	English