This Article Applies to:
TP-Link Routers
Issue Description/Phenomenon:
Some customers may report the speed is limited to 100 Mbps when connected to the TP-Link router, while the speed is much faster and can reach up to 500+ or 900+ Mbps when connecting to the ISP modem directly. If this is what you are experiencing, follow this article to get it resolved.
Troubleshooting Suggestions:
1. Mark certain you are getting a gigabit router, which has gigabit WAN/LAN ports. Some models like Archer C20 and Archer C50 only support 10/100 Mbps WAN/LAN ports, you can find that in the product specifications here and here. If your router only has 10/100 Mbps WAN/LAN ports, you cannot get a higher speed than 100 Mbps, and you need to get a gigabit router.
2. Login to the web GUI of the router, go to Basic > Network Map > click on the Icon for TP-Link router, slide down to the bottom of the page, and you will see the Negotiation Speed of the Ethernet ports in the Ethernet part. You can refer to this article to find more detailed instructions.
3. If the Internet Port Negotiation Speed is not 1000Mbps, go to Advanced > Network > Internet page, choose 1000Mbps Full Duplex, save and reboot the router:
4. If it's still connected at 100 Mbps, try with another Cat5e/6 cable or change the port of your ISP device, where you're connecting the TP-Link router (if possible).
5. If the Internet speed is negotiated correctly at 1000 Mbps, but the LAN gets stuck at 100 Mbps, it is also suggested to try with another Cat5e/6 cable between the router LAN and the client device, try with another client device if that is possible. Follow this thread to troubleshoot further.
6. Try to reset the router to the default factory following the FAQ.
7. Upgrade the router firmware to the latest. You can follow this guide.
If the speed still gets stuck at 100 Mbps after checking all the above, it is suggested to comment below and be sure to provide the following information:
1. Model number, hardware, and firmware version of your TP-Link Router.
2. What troubleshooting have you done, and what are the results? Send us the screenshots about the Negotiation speed.
3. What are the devices that you are testing the LAN speed, and what are the models of the adapters?
4. When did you purchase the TP-Link router, and when did the issue begin to happen?
5. What is the model of the ISP modem that this TP-Link router connects to?
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