18-13
Cisco IE 3000 Switch Software Configuration Guide
OL-13018-03
Chapter 18 Configuring STP
Configuring Spanning-Tree Features
Changing the Spanning-Tree Mode.
The switch supports three spanning-tree modes: PVST+, rapid PVST+, or MSTP. By default, the switch
runs the PVST+ protocol.
Beginning in privileged EXEC mode, follow these steps to change the spanning-tree mode. If you want
to enable a mode that is different from the default mode, this procedure is required.
To return to the default setting, use the
no spanning-tree mode
global configuration command. To
return the port to its default setting, use the
no spanning-tree link-type
interface configuration
command.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
spanning-tree mode
{
pvst
|
mst
|
rapid-pvst
}
Configure a spanning-tree mode.
•
Select
pvst
to enable PVST+ (the default setting).
•
Select
mst
to enable MSTP (and RSTP). For more configuration
steps, see
Chapter 19, “Configuring MSTP.”
•
Select
rapid-pvst
to enable rapid PVST+.
Step 3
interface
interface-id
(Recommended for rapid-PVST+ mode only) Specify an interface to
configure, and enter interface configuration mode. Valid interfaces
include physical ports, VLANs, and port channels. The VLAN ID range
is 1 to 4094. The port-channel range is 1 to 6.
Step 4
spanning-tree link-type point-to-point
(Recommended for rapid-PVST+ mode only) Specify that the link type
for this port is point-to-point.
If you connect this port (local port) to a remote port through a
point-to-point link and the local port becomes a designated port, the
switch negotiates with the remote port and rapidly changes the local
port to the forwarding state.
Step 5
end
Return to privileged EXEC mode.
Step 6
clear spanning-tree detected-protocols
(Recommended for rapid-PVST+ mode only) If any port on the switch
is connected to a port on a legacy IEEE 802.1D switch, restart the
protocol migration process on the entire switch.
This step is optional if the designated switch detects that this switch is
running rapid PVST+.
Step 7
show spanning-tree summary
and
show spanning-tree interface
interface-id
Verify your entries.
Step 8
copy running-config startup-config
(Optional) Save your entries in the configuration file.