The Ethernet is stuck in a "Identifying..." state or a "Cable unplugged" loop.
The Ethernet is stuck in a "Identifying..." state or a "Cable unplugged" loop.
I purchased a 15M cat5e cable recently and it stopped functioning right away. Initially, I suspected I might have damaged it during installation, but after verifying the adapter settings, it kept looping. After repeatedly unplugging both the router and the computer, the issue persisted, so I assumed something was broken. After about three hours of continuous failure, it suddenly worked perfectly again, which made me think it might have been a temporary glitch before it reset itself.
In addition to switching to a different cable between the same devices: Keep power wires away from the cable. I’ve experienced similar problems before and reduced the speed to 100mbps using a standard Ethernet cable that likely lacked shielding—it probably came from a more affordable source. Any intersection of Ethernet with electrical wiring should be oriented at a right angle (180 degrees) to limit overlap. This approach has worked well even with higher-power internal wiring that runs alongside regular power cables for device adaptors. Connect the cable to a switch and another device, and run a test for cable length. While not conclusive, if the switch measures the expected distance, the issue might be elsewhere—possibly other connected devices or the overall path the cable follows.
Cable connection is functioning but speed has dropped to 100mbps now. It seems proximity to power lines is affecting performance, so upgrading to a shielded cable might be necessary. For clarity, installation typically takes 3–5 hours once connected or after a system restart.
We haven't verified completely that the power wires are the exact source unless you have the same shorter wire along the identical route and it exhibits the same problem. Still, it's possible the shorter wire performs better at handling transmission, reducing the same electrical interference seen with the longer cable. Using a different high-quality cable from another brand might help, and opting for a shielded cable could be beneficial if the issue is indeed near power wires.
I’m sure it’s the cable, so I’ll go ahead and replace it. I’ll check it out after removing it from the wall to confirm if the issue is related to the nearby power cables.
Grounding one end of shielded cables is essential; consider starting with a CAT6a cable.