Router Operation

Interpreting Back-Panel LEDs

N o t e

All Net Fail LEDs are lit while the Reset button is pressed.

Tx (green) LED: This LED blinks each time a packet is transmitted through the related port. The frequency shows the amount of traffic. During periods of heavy traffic, it may look like it is lit all of the time. On WAN ports, Tx may seem to indicate heavy traffic when using bit-oriented protocols; however, Tx is lit for each packet delimiter (flag) whether packets are sent or not.

Insert (Green) LED: This LED is lit for a token ring port whenever the port is inserted into the ring.

Rx (green) LED: Depending on the type of port, this LED has one of two meanings:

Ethernet, WAN, and FDDI Ports: The Rx LED blinks each time a packet is received through the port. The frequency shows the amount of traffic. During periods of heavy traffic, it may look like it is lit all of the time. On WAN ports, Rx may seem to indicate heavy traffic when using bit-oriented protocols; however, Rx is lit for each packet delimiter (flag) whether packets are received or not.

Token Ring Port: The Rx LED is lit continuously if the token ring port is inserted in a ring and is receiving any packets or tokens.

AUI and BNC (green) LEDs: On Ethernet/802.3 ports having both an AUI and a BNC connector, one or the other of these two LEDs is lit to indicate which connector (AUI or BNC) the router is using. At power-on, boot, or reset, the router selects the proper connector by sensing the presence of an attached cable on one or the other of the connectors. If no cable is attached to either connector at power-on, boot, or reset (or if the port has been disabled through Quick Configuration or the Configuration Editor), then either the AUI or BNC LED may be lit.

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