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10-14
Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-09
Chapter 10 Configuring Interface Characteristics
Configuring Ethernet Interfaces
Setting the Interface Speed and Duplex Parameters
Beginning in privileged EXEC mode, follow these steps to set the speed and duplex mode for a physical
interface:
Use the no speed and no duplex interface configuration commands to return the interface to the default
speed and duplex settings (autonegotiate). To return all interface settings to the defaults, use the default
interface interface-id interface configuration command.
This example shows how to set the interface speed to 10 Mbps and the duplex mode to half on
FastEthernet interface 0/3:
Switch# configure terminal
Switch(config)# interface fastethernet0/3
Switch(config-if)# speed 10
Switch(config-if)# duplex half
Configuring Inline Power on the Catalyst 3550-24PWR Ports
The Catalyst 3550-24PWR switch automatically supplies inline power to connected Cisco IP Phones,
Cisco Aironet Access Points, and IEEE Power Devices if it senses no power on the circuit. If there is
power on the circuit, the switch does not supply it. You can also configure the Catalyst 3550-24PWR
switch to never supply power to these devices and to disable the inline-power detection.
For certain IEEE Power Devices that require multiple reloads during initialization, you can set a delay
shutdown time to configure the switch to continue providing power during initialization. For more
information about configuring a delay shutdown time, refer to the command reference for this release.
Note
This feature is only supported on the Catalyst 3550-24PWR switch.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
interface interface-id
Enter interface configuration mode and the physical interface
identification.
Step 3
speed {10 | 100 | 1000 | auto | nonegotiate} Enter the appropriate speed parameter for the interface, or enter auto
or nonegotiate.
Note
The 1000 keyword is available only for 10/100/1000 Mbps
ports. 100BASE-FX ports operate only at 100 Mbps. GBIC
module ports operate only at 1000 Mbps. The nonegotiate
keyword is available only for 1000BASE-SX, -LX, and -ZX
GBIC ports.
Step 4
duplex {auto | full | half}
Enter the duplex parameter for the interface.
Note
100BASE-FX ports operate only in full-duplex mode.
Note
This keyword is not available on GBIC ports.
Step 5
end
Return to privileged EXEC mode.
Step 6
show interfaces interface-id
Display the interface speed and duplex mode configuration.
Step 7
copy running-config startup-config
(Optional) Save your entries in the configuration file.