STP and Alternating Port Lights

[nelson.garcia]

I setup a STP topology with 5 Cisco 3560G switches. Everything is working correctly I assume, switches show correct blocked ports, root switches are set, al traffic is great.

One thing I see happening though is that on one of my root switches, one of the ports connecting to an access switch is blinking amber and green, alternating. Anyone ever have this problem? What does this mean?

[Leo Laohoo · Accepted solution]

Check the duplex settings.  Most of the time if you see alternating green/amber lights it means you have line errors, such as collisions, on your port.

[Leo Laohoo]

Thanks for the ratings Nelson.