Cisco Catalyst 4500 Series Administration Guide

23-7
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 disable a Flex Links backup interface, enter the no switchport backup interface interface-id
interface configuration command.
This example shows how to configure an interface with a backup interface and to verify the
configuration:
Switch# configure terminal
Switch(conf)# interface fastethernet1/1
Switch(conf-if)# switchport backup interface fastethernet1/2
Switch(conf-if)# end
Switch# show interface switchport backup
Switch Backup Interface Pairs:
Active Interface Backup Interface State
------------------------------------------------------------------------
FastEthernet1/1 FastEthernet1/2 Active Up/Backup Standby
FastEthernet1/3 FastEthernet1/4 Active Up/Backup Standby
Port-channel1 GigabitEthernet1/1 Active Up/Backup Standby
To configure a preemption scheme for a pair of Flex Links, perform this task:
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 64.
Step 3
Switch(conf-if)# switchport backup interface
interface-id
Configures a physical Layer 2 interface (or port channel)
as part of a Flex Links pair with the interface. When one
link is forwarding traffic, the other interface is in standby
mode.
Step 4
Switch(conf-if)# switchport backup interface
interface-id preemption mode [forced | bandwidth
| off]
Configures a preemption mechanism and delay for a Flex
Links interface pair. You can configure the preemption
mode as:
• forced—The active interface always preempts the
backup.
• bandwidth—The interface with higher bandwidth
always acts as the active interface.
• off—No preemption occurs from active to backup.
Step 5
Switch(conf-if)# switchport backup interface
interface-id preemption delay delay-time
Configures the delay time until a port preempts another
port.
Note Setting a delay time requires forced or bandwidth
mode.
Step 6
Switch(conf)# end
Returns to privileged EXEC mode.
Step 7
Switch# show interface [interface-id] switchport
backup
Verifies the configuration.
Step 8
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