Ok, so strange one, I have MikroTik hAP Lite out at a clients place.
Port 2 was connected with a Lan Cable, approx 70m (underground in PVC Pipe) to another network switch.
One Late afternoon, the connection stopped working.
I checked the preceding network switch and cable, and no problems there.
But Ports 2 and 4 on the hAP Lite show a link light, even when the cable is unplugged.
The hAP Lite had defaulted to a default configuration, I connected via Winbox on WIFI, and saw that my backup of the Config (as well as the other files I had saved on it) were all in tact. I tried to restore the config, but it was giving me errors, saying that the file does not exist.
I did a factory reset, and a netinstall of the latest firmware.
Ports 2 and 4 still show constant link on the hAP, but when I connect them to a switch, the switch does not have a link light at all.
Port 1 and 3 work fine.
My guess is that the part that controls Port 2 and 4 has died. Maybe as a result of a induced surge (Perhaps a nearby lightning strike induced a surge in the long outdoor cable?)
Does this sound plausible. I have already ordered a replacement hAP lite for them, but would just like to see if there is a plausible explanation.
Your port seems boken. But try with a new cable directly connected. If this show the same. it may be lightning, something with poe to cable or something like this that have bruoke your device.
I’m having exactly the same problem with hEX lites.
The only thing I can think of that might be causing the problem is static discharges, but it seems extraordinary that Ethernet ports would be so fragile. (I can’t imagine that they wouldn’t have circuitry to protect against static discharges.) If this is the case (and it’s only a hypothesis), then the problem might be because the units have plastic cases.
Unfortunately, I don’t know what is physically wrong with the devices, just that they’re behaving in the way you’ve described.
My guess is some static discharge as well. Induced voltage spikes could reach several hundred volts easily if some lightning discharge happened nearby. The amount of energy, induced in cable, is usually low, but enough to fry an ethernet port.
For this kind of connection, I’d use STP cable, with shield grounded at one end only (to avoid any spurious currents between two locations). And that is properly grounded, not just using STP connector plugged into ethernet device (hAP or any other).
Well, I will be installing a replacement hAP lite tomorrow, so that will solve the problem.
I have put the faulty one on my home network for playing around (will just use Eth1 and Eth3, no big deal)