Cisco Systems IC-23 manual IC-57, LED Trouble Indicators continued

Configuring LAN Interfaces

Configuring a LAN Extender Interface

Table 4	LED Trouble Indicators (continued)
SYSTEM OK		On Steady	Lights when the unit passes the power on diagnostics. This
			indicates proper operation.
		Blinking	Blinks while running startup diagnostics, then goes on
			steady.
			Blinking after the start-up diagnostics indicates that a
			system error has been encountered. Contact your system
			administrator who will have you disconnect and then
			reconnect the power to recycle your LAN Extender. If the
			blinking continues, check your WAN connection and the
			RX and TX LEDs.
		Off	An error condition has occurred. Contact your system
			administrator who will ask you to disconnect the power
			cord and then reconnect it to re-establish power to your
			LAN Extender.
LED		Condition	Meaning
ISDN B1and		Flicker	The serial line is transmitting and receiving packets
ISDN B2			normally.
		Blinking	A line fault has been detected. The LEDs will go on for
			several seconds and then they will blink a certain number
			of times to indicate a particular error. The LEDs will blink
			at a rate of one to two blinks per second. The following are
			the errors that can be encountered:
			1 blink = The serial line is down.
			2 blinks = No clock signal was received.
			3 blinks = An excessive number of cyclic redundancy
			check (CRC) errors has been received.
			4 blinks = The line is noisy.
			5 blinks = A loopback condition has occurred.
			6 blinks = The PPP link has failed.
			Contact your system administrator.
LAN TX and		Flicker	The Ethernet LAN connection is transmitting and receiving
LAN RX			data normally.
COLLISION			Detects data collisions.
LINK OK		Steady	Indicates that the serial link is up and functioning.

For more complete network troubleshooting information, refer to the Troubleshooting Internetworking Systems publication.

Cisco IOS Interface Configuration Guide

IC-57