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 backbonefast
spanning-tree backbonefast
To enable BackboneFast on a spanning-tree VLAN, use the spanning-tree backbonefast command. To
disable BackboneFast, use the no form of this command.
spanning-tree backbonefast
no spanning-tree backbonefast
Syntax Description This command has no arguments or keywords.
Defaults BackboneFast is disabled.
Command Modes Global configuration mode
Command History
Usage Guidelines BackboneFast should be enabled on all Catalyst 4506 series switches to allow the detection of indirect
link failures. Enabling BackboneFast starts the spanning-tree reconfiguration more quickly.
Examples This example shows how to enable BackboneFast on all VLANs:
Switch(config)# spanning-tree backbonefast
Switch(config)#
Related Commands
Release Modification
12.1(8a)EW Support for this command was introduced on the Catalyst 4500 series switch.
Command Description
spanning-tree cost Calculates the path cost of STP on an interface.
spanning-tree portfast default Enables PortFast by default on all access ports.
spanning-tree portfast (interface
configuration mode)
Enables PortFast mode.
spanning-tree port-priority Prioritizes an interface when two bridges compete for
position as the root bridge.
spanning-tree uplinkfast Enables the UplinkFast feature.
spanning-tree vlan Configures STP on a per-VLAN basis.
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