LAN/NIC problem

[ubuntuGuy]

this is more of a question. I have recently connected my Pine64 to a switch instead of connecting it directly to router and noticed that the green light started  to blink slowly(every 2-3 seconds) instead of solid green. I tried a different cable and different ports on the switch but the same result. Does it mean my nic is going bad or it is something else. any help will be appreciated.

The green led steadily blinking is an indication of GbE link... solid on is 100M AFAIK there is no official convention... different manufacturers like to do different things to keep us all guessing

thanks for the info