Issue:
link LED flashing on Ethernet Extenders

Solution:
The User Guide states:

Blinking – The link is training (trying to establish a link) or data is being received.


If the Eth LED is not blinking on either unit then the Interlink is trying to establish the link. If any of the Eth LED's are blinking then it becomes harder to differentiate data traffic from link establishment.

To verify if it is link establishment blinking, disconnect all ethernet devices from both ends to remove any data from being sent/received.