How is this possible??

[pds]

I just had to re-route an ethernet cable in the office and it required me to cut off the rj45 and replace it after rethreading the cable through the new route.

I cut off the end so I'd remake the cable the same way - looking at the bottom of the rj left to right - wo-o-wg-b-wb-g-wbr-br.
When I remade the end I built it backwards, switch the striped an the solid. i.e. o-wo-b-wg-g-wb-br-wbr.

Now that's possible because, brain fart. But the real Q is how come when I plugged it in - it worked!!!
The next day I was fiddling with the end I had cut off and got to thinking this is not how I made the new end. I pulled it out this am and - backwards.

So I made a new end the right way and plugged it in and - Violah! of course it worked. But - why did they both work?

 

[SGilbert]

Beats me!
Why do USB-C & Lightning plugs work downside up & upside down? Sure hope you don't stay up all night tonight pondering this stuff!

FWIW, I would have made a bigger hole for the plug.

 

[Satcomer]

The original installer made have made the same mistake seems the possible answer! Don't over think the situation just break a sigh of relief that your error made it work! As retired Network Tech I have seemed so-called experts make that very mistake from time to time and just made laugh!

 

[pds]

Not loosing sleep- for sure.
Bigger holes - my kinda solution.
But we had to pull it out of many through-the-wall spots to run it through the basement, so - OFF WITH ITS HEAD!!!

I had a high school computer club help me make cables in another life. Some of them had 6 wires right and the brown pair backwards and the cables wouldn't work. Back in the day I had a coax ethernet set up in a newsroom in Cairo. Sometimes leaving off a terminator made the network crash, but if you took off another one somewhere else it would solve conflict problems.

Ethernet==Vodoo!