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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter10 Configuring STP Configuring Basic STP Features
Configuring Basic STP Features
These sections include basic STP configuration information:
•Default STP Configuration, page 10-21
•Disabling STP, page 10-22
•Configuring the Root Switch, page 10-22
•Configuring a Secondary Root Switch, page 10-24
•Configuring STP Port Priority, page 10-26
•Configuring STP Path Cost, page 10-27
•Configuring the Switch Priority of a VLAN, page 10-28
•Configuring the Hello Time, page 10-29
•Configuring the Forwarding-Delay Time for a VLAN, page 10-29
•Configuring the Maximum-Aging Time for a VLAN, page 10-30
•Configuring STP for Use in a Cascaded Stack, page 10-30
•Displaying STP Status, page 10-31
For advanced configuration information, see the “Configuring Advanced STP Fe atur es” sec tion on
page 10-32.

Default STP Configuration

Table10-3 show s the de faul t STP c onf igurat ion.
Table10-3 Default STP Configuration
Feature Default Setting
Enable state Enabled on VLAN 1.
Up to 128 spanning-tree instances can be
enabled.
Switch priority 32768.
Spanning-tree port priority (configurable on a per-interface basis—used on
interfaces configured as Layer 2 access ports) 128.
Spanning-tree port cost (configurable on a per-interface basis—used on
interfaces configured as Layer 2 access ports) 1000 Mbps: 4.
100 Mbps: 19.
10 Mbps: 100.
Spanning-tree VLAN port priority (configurable on a per-VLAN ba sis —used
on interfaces configured as Layer 2 trunk ports) 128.
Spanning-tree VLAN port cost (configurable on a per-VLAN basis—used on
interfaces configured as Layer 2 trunk ports) 1000 Mbps: 4.
100 Mbps: 19.
10 Mbps: 100.
Hello time 2 seconds.