20-12
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 20 Configuring STP
Configuring Spanning-Tree Features
For more information about switch stacks, see Chapter 5, “Managing Switch Stacks.”
Configuring Spanning-Tree Features
These sections contain this configuration information:
Default Spanning-Tree Configuration, page 20-12
Spanning-Tree Configuration Guidelines, page 20-13
Changing the Spanning-Tree Mode., page 20-14 (required)
Disabling Spanning Tree, page 20-15 (optional)
Configuring the Root Switch, page 20-15 (optional)
Configuring a Secondary Root Switch, page 20-17 (optional)
Configuring Port Priority, page 20-18 (optional)
Configuring Path Cost, page 20-20 (optional)
Configuring the Switch Priority of a VLAN, page 20-21 (optional)
Configuring Spanning-Tree Timers, page 20-22 (optional)

Default Spanning-Tree Configuration

Table 20-3 shows the default spanning-tree configuration.
Tab le 20-3 Default Spanning-Tree Configuration
Feature Default Setting
Enable state Enabled on VLAN 1.
For more information, see the “Supported
Spanning-Tree Instances” section on
page 20-10.
Spanning-tree mode PVST+. (Rapid PVST+ and MSTP are
disabled.)
Switch priority 32768.
Spanning-tree port priority (configurable on a per-interface basis) 128.
Spanning-tree port cost (configurable on a per-interface basis) 1000 Mb/s: 4.
100 Mb/s: 19.
10 Mb/s: 100.
Spanning-tree VLAN port priority (configurable on a per-VLAN basis) 128.