Cisco Systems OL-6426-02 Configure WAN Interfaces, Configure the Fast Ethernet WAN Interface

Chapter 1 Basic Router Configuration

Configuring Basic Parameters

Configure WAN Interfaces

The Cisco 1811 and Cisco 1812 routers each have two Fast Ethernet interfaces for WAN connection. The Cisco 1801, Cisco 1802, and Cisco 1803 routers each have one ATM interface for WAN connection.

Based on the router model you have, configure the WAN interface(s) using one of the following procedures:

•Configure the Fast Ethernet WAN Interface

•Configure the ATM WAN Interface

Configure the Fast Ethernet WAN Interface

This procedure applies only to the Cisco 1811 and Cisco 1812 router models. Perform these steps to configure the Fast Ethernet interfaces, beginning in global configuration mode.

	Command	Purpose
Step 1
	interface type number	Enters the configuration mode for a Fast
		Ethernet WAN interface on the router.
	Example:	Note Fast Ethernet WAN ports are numbered
	Router(config)#interface fastethernet 0	0–1 on the Cisco 1800 series routers.
	Router(config-int)#
Step 2
	ip address ip-address mask	Sets the IP address and subnet mask for the
		specified Fast Ethernet interface.
	Example:
	Router(config-int)#ip address 192.1.12.2
	255.255.255.0
	Router(config-int)#
Step 3
	no shutdown	Enables the Ethernet interface, changing its
		state from administratively down to
	Example:	administratively up.
	Router(config-int)# no shutdown
	Router(config-int)#
Step 4
	exit	Exits interface configuration mode and returns
		to global configuration mode.
	Example:
	Router(config-int)# exit
	Router(config)#

Repeat these steps for the other Fast Ethernet WAN interface if desired.

Note Due to a limitation on the internal transceiver of the on-board layer-3 Fast Ethernet interfaces available on Cisco 1812 Ethernet Access Routers, configuring the interface with a speed of 10 Mbps may cause some CRC errors to appear on the interface. This is an expected behavior of the Cisco 1812 routers on-board layer-3 Fast Ethernet interface.

Cisco 1800 Series Integrated Services Routers (Fixed) Software Configuration Guide

OL-6426-02 1-7