The Ethernet connection repeatedly restarts to 100Mbps
The Ethernet connection repeatedly restarts to 100Mbps
I just received a new motherboard with Intel's 2.5 Gbps network adapter. Every time I power on my computer, it keeps switching between 1Gbps and 100Mbps. I've reinstalled the driver "Intel Ethernet Controller (2) i225-V" version 1.0.2.6, adjusted the speed and duplex settings manually to 1.0Gbps Full Duplex, which resolved the issue. However, after restarting, it reverts back to 100Mbps even though the setting remains at 1.0Gbps Full Duplex. I'm confused and need guidance. On my previous motherboard, this didn't happen before upgrading.
Did you download the driver from Intel’s site and remove all previous drivers before installing? Have you changed your motherboard? Did you reinstall Windows from a fresh copy? Use a different Ethernet cable (Cat5e, Cat6, or Cat6a). What type of router is connected to this computer?
I removed the device manager and restarted the computer to reinstall everything. After that, I upgraded the motherboard, CPU, and storage drives. I also tried a different cable and connected it to my ROG router (Dad).
Review your network gear and related hardware. Some legacy routers and switches could force all connections to match the slowest device on the network. For instance, if one of your older units was operating at 100MB instead of gigabit speeds, the entire system would run at that slower rate. While this isn't a major concern with today's equipment, it's something to verify.
Consider these alternatives: Disconnect the cable from the router and connect it elsewhere, restart the router, perform a network reset on the adapter.
Additional points: Is there another network device between the Ethernet port on the PC and the router? How far is the Ethernet cable? Check for any sharp bends or visible damage in the cable. Are there nearby sources of electromagnetic interference?
I'll begin with the cable. 10 out of 100... Requires 2 pairs. 1000 uses 4 pairs. A cable acting oddly might cause this issue.
Consider using another device with a gigabit ethernet port to check for similar problems. If the issue persists, it probably relates to the network. When it resolves, the problem is likely on the device. This helps narrow down the cause by isolating factors.