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8-10
Catalyst 4500 Series, Catalyst 2948G, Catalyst 2948G-GE-TX, and Catalyst 2980G Switches Software Configuration Guide—Release 8.2GLX
78-15908-01
Chapter 8 Configuring Spanning Tree PortFast, BPDU Guard, BPDU Filter, UplinkFast, BackboneFast, and Loop Guard
Configuring PortFast
4/1 1005 not-connected 4 32 enabled 0
Console> (enable) show spantree portfast 4/1
Portfast:enable trunk
Portfast BPDU guard is disabled.
Portfast BPDU filter is disabled.
Console>
Note
When you enable PortFast between two switches, the system will verify that there are no loops in the
network before bringing the blocking trunk to a forwarding state.
Disabling PortFast
To disable PortFast on a switch or trunk port, perform this task in privileged mode:
This example shows how to disable PortFast on port 1 of module 4:
Console> (enable) set spantree portfast 4/1 disable
Spantree port 4/1 fast start disabled.
Console> (enable)
To reset PortFast on a switch or trunk port to its default settings, perform this task in privileged mode:
This example shows how to disable PortFast on port 1 of module 4:
Console> (enable) set spantree portfast 4/1 default
Spantree port 4/1 fast start set to default.
Console> (enable) show spantree portfast 4/1
Portfast:default
Portfast BPDU guard is disabled.
Portfast BPDU filter is disabled.
Console> (enable)
Task
Command
Step 1
Disable PortFast on a switch port.
set spantree portfast mod_num/port_num disable
Step 2
Verify the PortFast setting.
show spantree mod_num/port_num
Task
Command
Step 1
Reset PortFast to its default setting on a switch
port.
set spantree portfast mod_num/port_num default
Step 2
Verify the PortFast setting.
show spantree mod_num/port_num