My wired connection normally reaches about 1000/1000 Mbps over Cat5e, and I downloaded a large game at full speed yesterday. Today, Windows shows the Ethernet link capped at 10/10 Mbps. I unplugged and reconnected the cable at both ends, manually set Speed & Duplex to 1.0 Gbps, and temporarily disabled my antivirus, but nothing changed. I'm not using a VPN, and the cable hasn't been moved or handled. What else should I check to restore the normal connection speed?
3 Answers
A 10 Mbps link usually points to a physical connection or negotiation problem rather than an internet-speed issue. Try another Ethernet cable first, then move the cable to a different router or switch port. If possible, connect the computer near the router with a known-good cable; if gigabit returns, the original cable or its connectors are the likely cause.
The speed is negotiated between your computer and the router. If you manually forced the computer to 1 Gbps, the other end also needs to be configured consistently. With typical home routers, the better option is usually to set the computer back to Auto Negotiation and let both devices negotiate automatically. A router port that is failing or negotiating incorrectly can otherwise fall back to 10 Mbps.
Try restarting the router and checking whether another device gets normal wired speeds from the same port. If every device is slow, the router port or the ISP connection may be involved. If only this computer is affected, focus on the cable, router port, Ethernet adapter, and its driver.
How would I configure the router side? I’m not sure where that setting is.