Cisco SMB 110-16pp Amber Flashing light

[tlavens01]

hi there...I have a Cisco 110-16-PP SMB switch.  I have a cable connecting my Xfinity modem/router to a non-POE port on this switch.  The left LED light on this port is flashing Amber, and the right LED light is solid green. This suggests a network loop of some kind.  However, as a test, I unplugged everything else from the switch except the connection from the modem/router to the switch, and the flashing amber LED remains.  If there is nothing else connected to the switch, how can I have a network loop? Or is this a faulty switch?

thank you,

Trevor

[marce1000]

      - FYI : https://community.cisco.com/t5/switches-small-business/sg110-leds/m-p/3301777#M19339
        Check logs on the device too , and or when a connection attempt with a foreign device is attempted

 M.

[tlavens01]

Thanks. I’ve read this thread. It doesn’t answer my question. And given that this is an unmanaged switch, I don’t believe there are any logs. 

[marce1000]

  - Then that may be your 'fatal problem'  ; being an unmanaged switch which should be at all cost 
     avoided in modern networks (the use of them)
  .  Because there is no configuration handling possible if a connected device
     has special requirements concerning spanning tree , VTP , ... 

   M.

[tlavens01]

This didn’t answer the question about the switch. 

[marce1000]

  - The logic of the device is probably too simple (too) , to recover from that condition. Try a full power cycle , 

 M.

[tlavens01]

I Cycled the power. Same behavior. Note: I’m looking for an answer as to why a single connection (from a modem) to a switch would yield a flashing Amber, suggesting a network loop, when there isn’t a single other device connected to the switch. Suggesting I throw away the switch isn’t a solution. 

[marce1000]

  - If the light remains flashing Amber with no connections at all and after power up then the device could have a hardware problem.
    You may also try and look at the logs on the modem when the connection to the switch is made (if available)

                 >...Suggesting I throw away the switch isn’t a solution. 
    - Note that the forums are populated by customers based on best effort. For   for official Cisco support checkout :
        https://www.cisco.com/c/en/us/support/web/tsd-cisco-small-business-support-center-contacts.html

  M.