So, I've recently graduated with a shiny cybersecurity degree, got some CCNA certs under my belt, and have about a year and a half of IT experience. I'm currently running Windows 11 and facing a frustrating issue. My two network adapters, the 2.5GB Killer E3100G and a U-GREEN USB-A to RJ45 2.5GB adapter, are stuck negotiating at a maximum of 100 Mbps for both upload and download. I've tried switching to wireless and got decent speeds of 300 Mbps, so I know the system can handle more. My cable definitely supports 1G, as it works well on another machine. I've ruled out the cable, router, BIOS, and even the drivers after downloading fresh ones for both adapters. When I boot into Tails and check with ethtool, it shows that they can do 10/100/1000/2500, yet they're not. I'm really at a loss and considering spending $20-40 on a new adapter, but honestly, I'd rather fix this without more hassle. Any tips or ideas that I might have missed? Thanks!
3 Answers
It sounds like a classic case of cable issues! Have you double-checked the cables and connections? Sometimes it’s as simple as a bad bend or a faulty keystone that can lead to 100 Mbps max. If you can, try swapping out the cable or testing it in another device to rule it out completely. You might be surprised!
You really need to check everything that connects to your setup. Have you considered trying a different cable just to be sure? It's usually the culprit. Also, if you're using a managed switch, check its settings to ensure it’s not forcing a lower link speed. 9 times out of 10, it’s a cabling issue!
Exactly! And don’t forget to check the crimping on any connectors you might be using. Sometimes a bad pin can ruin the whole setup.
Check the settings in Device Manager! Right-click on your network adapter and navigate to Properties > Advanced tab. Look for "Speed & Duplex" and set it to the maximum instead of "Auto." That can sometimes resolve negotiation issues and get you back to higher speeds.
Agreed! I dealt with similar woes, and it turned out to be the cable all along. A fresh one fixed it right up for me!