Table of Contents
Advertisement
Chapter 9
Configuring Spanning-Tree PortFast, UplinkFast, BackboneFast, and Loop Guard
To enable PortFast on a switch port, perform this task in privileged mode:
Task
Step 1
Enable PortFast on a switch port that is connected
to a single workstation, switch, or server.
Step 2
Verify the PortFast setting on a switch port.
This example shows how to enable PortFast on port 1 of module 4 and verify the configuration; the
PortFast status is shown in the "Fast-Start" column:
Console> (enable) set spantree portfast 4/1 enable
Warning:Connecting Layer 2 devices to a fast start port can cause
temporary spanning tree loops. Use with caution.
Spantree port
Console> (enable) show spantree 4/1
Port
--------- ----
4/1
4/1
4/1
4/1
4/1
4/1
4/1
4/1
Console> (enable)
If the designation for a port is displayed as edge, that port is also a PortFast port. See the
Note
section on page
Enabling Spanning-Tree PortFast on a Trunk Port
You can use PortFast to connect a single end station or a switch port to a switch port. If you enable
Caution
PortFast on a port that is connected to another Layer 2 device, such as a switch, you might create network
loops.
To enable PortFast on a trunk port, perform this task in privileged mode:
Task
Step 1
Enable PortFast on a trunk port that is connected
to a single workstation, switch, or server.
Step 2
Verify the PortFast setting on a trunk port.
OL-8978-04
4/1 fast start enabled.
Vlan
Port-State
Cost
-------------
-----
1
blocking
100
forwarding
521
blocking
522
blocking
523
blocking
524
blocking
1003
not-connected
1005
not-connected
7-23.
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
Command
set spantree portfast mod_num/port_num enable
| disable
show spantree [mod_num/port_num] [vlan]
Priority
Fast-Start
--------
----------
19
20
enabled
10
20
enabled
19
20
enabled
19
20
enabled
19
20
enabled
19
20
enabled
19
20
enabled
19
4
enabled
Command
set spantree portfast mod_num/port_num enable
trunk
If you enter the set spantree portfast
Note
command on a trunk port without using
the trunk keyword, the trunk port will
stay in disable mode.
show spantree portfast [mod_num/port_num]
Configuring PortFast on the Switch
Group-method
------------
"Edge Ports"
9-9
Hide quick links:
Advertisement
Table of Contents
Troubleshooting
