I have a problem that seems odd to me. I have a small patch panel in my home which is wired to various outlets. Until recently, I was running my router (an Asus RT-N66U) near the panel but am now moving it so I got a switch (Cisco SG100D-08). On the other end of this particular port on the patch panel is a Linux box running a Realtek RTL8111/8168/8411 (Not sure which, that's just the lspci output)
So here is the problem: This works: Router - patch cable - patch panel - cat6 - cat5e socket - patch cable - linux This doesn't: Switch - patch cable - patch panel - cat6 - cat5e socket - patch cable - linux
However, this DOES work: Switch - patch cable - cat5e patch panel - cat6 - cat5e socket - patch cable - Laptop (Dell Inspiron)
All patch cables are pre-made and newish. I tried switching out patch cables, all patch cables work with the switch and the laptop but none of them work with the switch and the linux box.
The switch and the linux box are compatible as it links if plugged in directly.
If there was a problem with my wiring, surely it would not work with the router to my linux box, or with the switch to my laptop, but they link fine. I only get a problem when using a combination of the switch, my cat6 cabling and the Linux box. I did try cold booting the linux box to no avail.
Now obviously, I will be going over the patch panel wiring, but until then, I am confused on a theory level - is there something in ethernet cabling that could affect only certain combinations of devices?