Cisco Systems IC-23 Extending the 10BASE-T Capability, Configuring Fast Ethernet 100BASE-T, IC-27

Configuring LAN Interfaces

Configuring an Ethernet or Fast Ethernet Interface

Extending the 10BASE-T Capability

On a Cisco 4000 series or Cisco 4500 series routers, you can extend the twisted-pair 10BASE-T capability beyond the standard 100 meters by reducing the squelch (signal cutoff time). This feature applies only to the LANCE controller 10BASE-T interfaces. LANCE is the AMD controller chip for the Cisco 4000 and Cisco 4500 Ethernet interface.

	Note Does not apply to the Fast Ethernet interface.
	To reduce squelch, use the first command in the following table in interface configuration mode. You
	can later restore the squelch by using the second command.
Command		Purpose
squelch reduced		Reduces the squelch.
squelch normal		Returns squelch to normal.

Configuring Fast Ethernet 100BASE-T

You must configure the Fast Ethernet 100BASE-T interface on a Cisco AS5300 so that it can be recognized as a device on the Ethernet LAN. The Fast Ethernet interface supports 10- and 100-Mbps speeds with the 100BASE-T and 10BASE-T routers, hubs, and switches.

To configure the interface, use the following commands beginning in privileged EXEC mode:

	Command	Purpose
Step 1
	configure terminal	Enters global configuration mode.
Step 2
	interface fastethernet number	Enters Fast Ethernet interface configuration mode.
Step 3
	ip address address subnet-mask	Assigns an IP address and subnet mask to the interface.
Step 4	speed {10 100 auto}	Assigns a speed to the interface. The default is 100 Mbps.1
		For relationship between duplex and speed command options, see Table 3.
Step 5
	duplex {full half auto}	Sets up the duplex configuration on the Fast Ethernet interface. The default
		is half duplex.1
		For relationship between duplex and speed command options, see Table 3.

1. The auto option automatically negotiates the speed based on the speed and the peer router, hub, or switch media.

To use the auto-negotiation capability (that is, to detect speed and duplex modes automatically), you must set both speed and duplex to auto. Setting the speed to auto negotiates speed only, and setting duplex to auto negotiates duplex only. Table 3 describes the access server’s performance for different combinations of the duplex and speed command options. The specified duplex command option plus the specified speed command option produces the resulting system action.

Cisco IOS Interface Configuration Guide

IC-27