Disabling Spanning Tree - Cisco 3845 - Security Bundle Router Software Manual

Chapter 13 Configuring STP
Command
Step 3
interface interface-id
Step 4
spanning-tree link-type point-to-point
Step 5
end
Step 6
clear spanning-tree detected-protocols
Step 7 show spanning-tree summary
and
show spanning-tree interface
interface-id
Step 8 copy running-config startup-config
To return to the default setting, use the no spanning-tree mode global configuration command. To return
the port to its default spanning-tree mode setting, use the no spanning-tree link-type interface
configuration command.

Disabling Spanning Tree

Spanning tree is enabled by default on all ports in VLAN 1 and in all newly created VLANs up to the
spanning-tree limit specified in the
spanning tree only if you are sure there are no loops in the network topology.
Caution When spanning tree is disabled and loops are present in the topology, excessive traffic and indefinite
packet duplication can drastically reduce network performance.
Beginning in privileged EXEC mode, follow these steps to disable spanning-tree on a per-VLAN basis.
This procedure is optional.
Command
Step 1 configure terminal
Step 2 no spanning-tree vlan vlan-id
Step 3 end
OL-23400-01
Purpose
(Recommended only for rapid-PVST+ mode) Specify an STP port 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 26.
(Recommended only for rapid-PVST+ mode) Specify that the link type
for this port is point-to-point.
If you connect this 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.
Return to privileged EXEC mode.
(Recommended only for rapid-PVST+ mode) If any port on the switch
running spanning tree 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+.
Verify your entries.
(Optional) Save your entries in the configuration file.
"Supported Spanning-Tree Instances" section on page
Purpose
Enter global configuration mode.
For vlan-id, the range is 1 to 4094.
Return to privileged EXEC mode.
Cisco ME 3800X and 3600X Switch Software Configuration Guide
Configuring Spanning-Tree Features
13-9. Disable
13-13