Cisco Catalyst 4500 Series Administration Guide

23-8
Software Configuration Guide—Release IOS XE 3.6.0E and IOS 15.2(2)E
OL_28731-01
Chapter 23 Configuring Flex Links and MAC Address-Table Move Update
Configuring Flex Links
To remove a preemption scheme, enter the no switchport backup interface interface-id preemption
mode interface configuration command. To reset the delay time to the default, enter the
no switchport backup interface interface-id preemption delay interface configuration command.
This example shows how to configure preemption mode as bandwidth for a backup interface pair and to
verify the configuration:
Switch# configure terminal
Switch(conf)# interface gigabitethernet1/0/1
Switch(conf-if)# switchport backup interface gigabitethernet1/2
Switch(conf-if)# switchport backup interface gigabitethernet1/2 preemption mode forced
Switch(conf-if)# switchport backup interface gigabitethernet1/2 preemption delay 50
Switch(conf-if)# end
Switch# show interface switchport backup detail
Active Interface Backup Interface State
------------------------------------------------------------------------
GigabitEthernet1/21 GigabitEthernet1/2 Active Down/Backup Down
Interface Pair : Gi1/21, Gi1/2
Preemption Mode : forced
Preemption Delay : 50 seconds
Bandwidth : 10000 Kbit (Gi1/1), 10000 Kbit (Gi1/2)
Mac Address Move Update Vlan : auto
<output truncated>
Configuring VLAN Load Balancing on Flex Links
To configure VLAN load balancing on Flex Links, perform this task:
To disable the VLAN load balancing feature, enter the no switchport backup interface prefer vlan
interface configuration command.
In this example, VLANs 1 to 50, 60, and 100 to 120 are configured on the switch:
Switch(config)# interface fastethernet 1/6
Switch(config-if)# switchport backup interface fastethernet 1/0/8 prefer vlan 60,100-120
Command Purpose
Step 1
Switch# configure terminal
Enters global configuration mode.
Step 2
Switch(conf)# interface interface-id
Specifies the interface, and enters interface configuration
mode. The interface might be a physical Layer 2 interface
or a port channel (logical interface). The port channel
range is 1 to 48.
Step 3
Switch(conf-if)# switchport backup interface
interface-id prefer vlan vlan-range
Configures a physical Layer 2 interface (or port channel)
as part of a Flex Links pair with the interface, and
specifies the VLANs carried on the interface. The VLAN
ID range is 1 to 4094.
Step 4
Switch(conf-if)# end
Returns to privileged EXEC mode.
Step 5
Switch# show interfaces [interface-id] switchport
backup
Verifies the configuration.
Step 6
Switch# copy running-config startup config
(Optional) Saves your entries in the switch startup
configuration file.

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