Cisco Catalyst 3550

Chapter 1 Product Overview
Front-Panel Description
1-8
Catalyst 3550 Multilayer Switch Hardware Installation Guide
78-11358-01
Table 1-5 Meaning of LED Colors in Different Modes on the Catalyst 3550 Switch
Port Mode LED Color Meaning
STAT
(port status)
Off No link.
Solid green Link present.
Flashing green Activity. Port is transmitting or receiving data.
Alternating
green-amber
Link fault. Error frames can affect connectivity, and errors such as
excessive collisions, CRC errors, and alignment and jabber errors
are monitored for a link-fault indication.
Solid amber Port is not forwarding. Port was disabled by management or an
address violation or was blocked by Spanning Tree Protocol (STP).
Note After a port is reconfigured, the port LED can remain
amber for up to 30 seconds as STP checks the switch for
possible loops.
UTL
(utilization)
Green The port LEDs display backplane utilization on a logarithmic scale.
See Figure 1-4 for details.
Amber The peak total backplane utilization over the last 24 hours.
DUPLX
(duplex)
Off Port is operating in half duplex.
Green Port is operating in full duplex.
SPEED
10/100/1000 ports
Off Port is operating at 10 Mbps.
Green Port is operating at 100 Mbps.
Flashing green Port is operating at 1000 Mbps.
GBIC ports
Off Port is not operating.
Flashing green Port is operating at 1000 Mbps.