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Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide—Release 12.1 E
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Chapter 6 Configuring Interfaces
Configuring Optional Interface Features
Configuring Optional Interface Features
These sections describe optional interface features:
Configuring Ethernet Interface Speed and Duplex Mode, page 6-7
Configuring Jumbo Frame Support, page 6-10
Configuring IEEE 802.3Z Flow Control, page 6-14
Configuring the Port Debounce Timer, page 6-15
Adding a Description for an Interface, page 6-16

Configuring Ethernet Interface Speed and Duplex Mode

These sections describe how to configure Ethernet port speed and duplex mode:
Speed and Duplex Mode Configuration Guidelines, page 6-7
Setting the Ethernet Interface Speed, page 6-8
Setting the Interface Duplex Mode, page 6-8
Configuring Link Negotiation on Gigabit Ethernet Ports, page 6-8
Displaying the Speed and Duplex Mode Configuration, page 6-9

Speed and Duplex Mode Configuration Guidelines

You usually configure Ethernet port speed and duplex mode parameters to auto and allow the
Catalyst 6500 series switch to negotiate the speed and duplex mode between ports. If you decide to
configure the port speed and duplex modes manually, consider the following information:
If you set the Ethernet port speed to auto, the switch automatically sets the duplex mode to auto.
If you enter the no speed command, the switch automatically configures both speed and duplex to
auto.
If you configure an Ethernet port speed to a value other than auto (for example, 10, 100, or
1000 Mbps), configure the connecting port to match. Do not configure the connecting port to
negotiate the speed.
If you manually configure the Ethernet port speed to either 10 or 100 Mbps, the switch prompts you
to also configure the duplex mode on the port.
Note Catalyst 6500 series switches cannot automatically negotiate Ethernet port speed and duplex mode if the
connecting port is configured to a value other than auto.
Caution Changing the Ethernet port speed and duplex mode configuration might shut down and reenable the
interface during the reconfiguration.