Chapter 1 Product Overview
Front-Panel Description
1-18
Catalyst 3550 Multilayer Switch Hardware Installation Guide
78-11358-03
Table 1-8
Meaning of LED Colors in Different Modes on the Switch
Port Mode
LED Color
Meaning
STATUS
(port status)
Off
No link, or port was administratively shut down.
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 blocked by Spanning Tree Protocol (STP) and is not
forwarding data.
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.
Flashing amber Port is blocked by STP and is transmitting or receiving packets.
UTIL
(utilization)
Green
The port LEDs display backplane utilization on a logarithmic scale.
See
and
for details on the
Catalyst 3550-12T and 3550-12G switches. See
for details on the Catalyst 3550-24 and 3550-48
switches.
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 and 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.