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 vlan
Usage Guidelines When you are setting the max-age seconds value, if a bridge does not hear BPDUs from the root bridge
within the specified interval, it assumes that the network has changed and recomputes the spanning-tree
topology.
The spanning-tree root primary command alters the switch bridge priority to 8192. If you enter the
spanning-tree root primary command and the switch does not become root, then the bridge priority is
changed to 100 less than the bridge priority of the current bridge. If the switch does not become root, an
error will result.
The spanning-tree root secondary command alters the switch bridge priority to 16384. If the root
switch fails, this switch becomes the next root switch.
Use the spanning-tree root commands on backbone switches only.
Examples This example shows how to enable spanning tree on VLAN 200:
Switch(config)# spanning-tree vlan 200
Switch(config)#
This example shows how to configure the switch as the root switch for VLAN 10 with a network
diameter of 4:
Switch(config)# spanning-tree vlan 10 root primary diameter 4
Switch(config)#
This example shows how to configure the switch as the secondary root switch for VLAN 10 with a
network diameter of 4:
Switch(config)# spanning-tree vlan 10 root secondary diameter 4
Switch(config)#
Related Commands Command Description
spanning-tree cost Calculates the path cost of STP on an interface.
spanning-tree port-priority Prioritizes an interface when two bridges compete for
position as the root bridge.
spanning-tree portfast default Enables PortFast by default on all access ports.
spanning-tree portfast (interface
configuration mode)
Enables PortFast mode.
spanning-tree vlan Configures STP on a per-VLAN basis.
show spanning-tree Displays spanning-tree state 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