Installation guide

Overview 1-15
LEDs
Interpreting LEDs after a Mode Change
When you change port modes, the meaning of LED colors also changes. Table 1-5 explains
how to interpret the LED colors after you change the mode.
Table 1-5 Meaning of LED Colors in Different Modes
Port Mode LED Color Meaning
STATUS (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 status LED can
remain amber for up to 30 seconds as STP checks the switch for
possible loops.
UTL (utilization) Green The LEDs display backplane utilization on a logarithmic scale.
If all port status LEDs are green, the switch is using 50% or
more of its total bandwidth capacity. If the right-most LED is
amber, the switch is using less than 50% of its total bandwidth.
If the LED to the left of the right-most LED is amber, the
switch is using less than 25% of its total capacity, and so on.
See Figure 1-10, Figure 1-11, and Figure 1-12 for details.
DUPLEX Off Port is operating in half-duplex.
Green Port is operating in full-duplex.