Issue: Cisco Router Link Light Blinking Orange

The link light blinking orange on a Cisco router indicates a duplex mismatch error. In telecommunication, a duplex communication system refers to point-to-point communication and there are two types, namely full-duplex and half-duplex. In the half-duplex communication, only a single port can send or receive data at a time. On the other hand, in full-duplex, all nodes can send and receive data simultaneously. Continue reading this page to fix the issue Cisco router link light blinking orange.

Cisco's Router Link Light Blinking Orange Color

Cisco router link light blinking orange

To fix the blinking orange link light on your Cisco router, follow the steps mentioned below.

  • If the problem persists, enable the auto-MDIX (automatic medium dependent interface crossover) feature.
  • To do so, enter into global configuration mode and interface configuration mode.
  • Use the ‘S1(config-if)# duplex auto’ command to configure the interface to negotiate the duplex mode with the connected device automatically.
  • To automatically negotiate the speed with the connected devices, enter the ‘S1(config-if)# speed auto’ command.
  • To enable the auto-MDIX feature, enter ‘S1(config-if)# mdix auto’ in the Terminal window.
  • To exit and return to the privileged EXEC mode, enter ‘S1(config)# end’ in the Terminal window. 
  • To save the running configuration to startup configuration, use the ‘S1# copy running-config startup-config’ command.
  • This will fix the Cisco router link light blinking orange issue.