20-12
Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter20 Configuring Optional Spanning-Tree Features
Configuring Optional Spanning-Tree Features
Configuring Optional Spanning-Tree Features
These sections contain this configuration information:
Default Optional Spanning-Tree Configuration, page20-12
Optional Spanning-Tree Configuration Guidelines, page20-12
Enabling Port Fast, page20-13 (optional)
Enabling BPDU Guard, page20-14 (optional)
Enabling BPDU Filtering, page20-15 (optional)
Enabling UplinkFast for Use with Redundant Links, page 20-16 (optional)
Enabling Cross-Stack UplinkFast, page 20-17 (optional)
Enabling BackboneFast, page20-17 (optional)
Enabling EtherChannel Guard, page 20-18 (optional)
Enabling Root Guard, page20-18 (optional)
Enabling Loop Guard, page 20-19 (optional)

Default Optional Spanning-Tree Configuration

Table20-1 shows the default optional spanning-tree configuration.

Optional Spanning-Tree Configuration Guidelines

You can configure PortFast, BPDU guard, BPDU filtering, EtherChannel guard, root guard, or loop
guard if your switch is running PVST+, rapid PVST+, or MSTP.
You can configure the UplinkFast, the BackboneFast, or the cross-stack UplinkFast feature for rapid
PVST+ or for the MSTP, but the feature remains disabled (inactive) until you change the spanning-tree
mode to PVST+.
Table20-1 Default Optional Spanning-Tree Configuration
Feature Default Setting
Port Fast, BPDU filtering, BPDU guard Globally disabled (unless they are individually configured
per interface).
UplinkFast Globally disabled. (On Catalyst 3750 switches, the
UplinkFast feature is the CSUF feature.)
BackboneFast Globally disabled.
EtherChannel guard Globally enabled.
Root guard Disabled on all interfaces.
Loop guard Disabled on all interfaces.