The other day cable-test features of Mikrotik/Ros happened to be mentioned here:
http://forum.mikrotik.com/t/hap-ax2-poe-port-suddenly-limited-to-100mbps/181713/1
and I remained with the curiosity about what each cable pair line/entry meant (the order they are shown could be either by wire colour/twisted pair or couple of pins on rj45, i.e. 1 and 2, 3 and 6, 4 and 5, 7 and 8 ), so I dig out of the box of things that may come useful one day an old (defective) self-crimped cable some 3 m long, then, with a probability of success of 50% I cut off one of the connectors.
Then tested the cable with a keystone socket and an already tested patch cable and I was lucky, the remaining connector and cable was good.
I had a hap lite handy (v6.49.17) and tested the cable-detect feature shorting the wires in every possible permutation (tried two ports, ether 3 and ether 4, to rule out the possibility that one port was defective).
The hap lite I have is the “tower” version (RB941-2nD-TC) but it should work the same as the “flat” version RB941-2nD (which is listed among the devices that sport the cable-detect feature) here:
https://help.mikrotik.com/docs/spaces/ROS/pages/8323191/Ethernet
Maybe the feature does not work properly specifically on the hap lite model I have, or maybe 6.49.17 is an unlucky release, but results were if not senseless, completely crazy.
The only pair short that is detected properly is 1-2 (Green and White/Green in T568A) and it is shown as shorted as second entry.
Short on pair 3-6 (Orange and White/Orange in T568A) can be detected indirectly as it creates a unique pattern (all entries BUT the second shown as shorted).
The rest was more or less “a suffusion of yellow”.
It could make sense that, since the device has no PoE and has 10/100 interfaces, only 1,2 and 3,6 pairs are analyzed/detected (even if “strangely”), but then the output should show that.
I did a couple more tests with good (but maybe too short) patch cables, simulating the shorts on a keystone socket, but the results were substantially the same as the ones in the image.
I will do some more tests with longer cables when I have some time, I should have a few 10 m ones somewhere …
