Why is my speed limited to 100Mbps on wired Ethernet inside the house?
Why is my speed limited to 100Mbps on wired Ethernet inside the house?
Hello,
I recently moved into a new house built in 2018 that includes Ethernet ports throughout. They weren’t labeled, but I’ve now identified which port near my router corresponds to which in other rooms.
I’ve tried connecting my game console through the lounge port, then from the router’s related port, and finally back into the router. I expected around 500Mbps, which I do get when testing via WiFi, but the console only receives 100Mbps.
I’ve checked several things: plugging directly into the router increased speeds to 500Mbps, tested both cables, confirmed the ports use T568B, and verified all other ports in the house also give 100Mbps. I’m still trying to understand why the speed is so low.
Anyone have suggestions on what might be causing this issue? Also, please give me a chance—I’m still getting familiar with all this!
There are several potential causes. The main issue is likely bad terminations on the in-wall wiring. Another common mistake is using an outdated 100Mbit ethernet switch instead of a gigabit model. A third possibility is that your laptop only has 100Mbit hardware. Additionally, damage to one of the eight wires in your Ethernet port could be responsible.
Adjust the Ethernet speed, launch Device Manager, go to Properties-Advanced for the network adapter, choose Speed and Duplex under the Property section, and click the Value dropdown to expand.
Thank you for your feedback! Would it make sense to rewire two ports to check if that improves things? Also, I’m uncertain whether there’s a switch involved or if it’s just a direct connection—have you searched around your home for any switches? I believe the issue isn’t with the laptop since I’ve used it wired before and achieved much better speeds.
bad cabling or router.
disconnect all lan ports except one and test from that end. also check the connection speed by examining the ethernet interface status in network properties.
if you have a damaged and shorted cable, the issue will appear immediately upon plugging it in.
otherwise, there may be other problems such as excessive cable length, bends in the wire, or incorrect cable type causing heat damage.
plenum grade in residential walls and attic shows signs of degradation, especially if runs have twists or kinks in the wire. The reported speeds likely stemmed from an internet speed test rather than the actual connection speed. I set up my own networks, including a 10Gb and 1Gb connection about 15 years ago, both using CAT 6 CMX wire without any problems. Now that CAT 8 CMX bulk is more affordable, I plan to upgrade to it and use the spare CAT 6 for distributed audio.
Usually, if something breaks down badly, you'll face more problems than just slower performance and restrictions that match the Cat5 limit feels a bit too perfect.
It seems they are using Cat5e, as indicated by the port labels (though they might have also used Cat5 cable).
The speeds measured during tests match what the ports display, and the maximum rates listed for each device are around 100Mbps when connected to the wall ports.
When connected directly to the router, performance increases significantly to 1Gb.