Cisco Catalyst 4500 Series Command Reference Guide

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Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.4.0SG and IOS 15.1(2)SG)
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Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
spanning-tree loopguard default
spanning-tree loopguard default
To enable loop guard as the default on all ports of a specific bridge, use the spanning-tree loopguard
default command. To disable loop guard, use the no form of this command.
spanning-tree loopguard default
no spanning-tree loopguard default
Syntax Description This command has no keywords or arguments.
Defaults Loop guard is disabled.
Command Modes Global configuration mode
Command History
Usage Guidelines Loop guard provides an additional security in the bridge network. Loop guard prevents alternate or root ports
from becoming the designated port because of a failure leading to a unidirectional link.
Loop guard operates only on ports that are considered point-to-point by the spanning tree.
Individual loop-guard port configuration overrides this global default.
Examples This example shows how to enable loop guard:
Switch(config)# spanning-tree loopguard default
Switch(config)#
Related Commands
Release Modification
12.1(12c)EW Support for this command was introduced on the Catalyst 4500 series switch..
Command Description
spanning-tree guard Enables root guard.
show spanning-tree Displays spanning-tree information.

Cisco Catalyst 4500 Series Specifications

General

Series	Catalyst 4500 Series
Category	Switch
Layer Support	Layer 2, Layer 3
Form Factor	Modular chassis
Stackable	No
Chassis Slots	3, 6, 7, 10
Power Supply Options	AC, DC
Redundancy	Power supply, Supervisor engine
Network Management	Cisco IOS Software CLI, SNMP, Cisco Prime Infrastructure
Features	Security, QoS
Port Density	Up to 384 ports per chassis
Security Features	802.1X, ACLs, DHCP Snooping, Dynamic ARP Inspection, IP Source Guard
Supervisor Engine	8-E