Troubleshooting What if my Router Speed is capped at 100 Mbps?
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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Thank you. We would like to investigate this on our end as well. When you have time and if you are willing can you please respond to the email from support.forum@tp-link.com?
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Hi, I've tried all the above mentioned fixes. But none of them have worked. I also checked the speed on the ISP's end, which is perfectly as advertised. The TP-link router however is stuck at 100Mbps full duplex.
I went into the advanced settings and set the negotiation speed to 1000Mbps full duplex as well.
Here are all the specs of the router:
Archer C6
Hardware Version: v2.0
Firmware Version: 1.3.6 Build 20200902 rel.65591(4555)
This had happened once last year but was some how fixed automatically, unsure how to deal with this recurring issue. Any help is appreciated.
Thanks
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Mine is working fine a week ago and working above 100mbps using LAN connection.
Wifi is still fine giving me nearly 200mbps.
I wonder why my router LAN port is now capped at 100mbps.
Router: AX1500 (two weeks old)
Help is much appreciated.
Thank you.
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We strongly suggest you either change the cable between your ISP modem and C6 with another one (Cat5e/6) or use another LAN port on your ISP modem to connect to C6. It's best to use a new Cat5e/6 cable.
BTW, what's the brand and model of the ISP modem? Will you get a stable speed when connecting a computer directly to it with the Ethernet cable? This needs to be tested and confirmed first, as we need to know if this is caused by the cable connectivity or the modem LAN.
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Can we confirm what are the devices and models of the adapters that connected to the LAN ports of the AX1500 via cables?
Have you tried other suggestions, such as changing with different/new cat 5e/6 cables, or testing with other wired devices to check if it can negotiate at 1000Mbps automatically, try other LAN ports?
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Looks there is a BUG, because, after doing all the changes, the speed was ok, but suddely the limit was estabished again around 100Mb. Without any change in the configuration, I turned off the router and the ISP router, and then the speed was back to normal. After some time, the speed is limited again without any change.... this process was was done more than 5 times during the week and the same behaviour happened every time.
Tests were done using cable and wifi... Like I mentioned, without any change, the speed is limited, and just restarting the routers (AX50 and ISP), the speed is back to normal. Important to mentioned that ISP model was all the time performing well.
Model : AX50 (US) v 1.0
Firmware : 1.0.9 Build 20200708 rel.55037(5553)
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When the speed drops to 100Mbps, how about the Negotiation Speed displayed on the router web GUI? Please send us a screenshot, thanks.
Meanwhile, have you choose 1000Mbps Full-Duplex under Advanced > System Tool > System Parameters? It's strongly suggested to try with a different cat 5e/6 cable, both the cables from the modem to the router and the cable from the router to the device need to be good. Cables do go bad especially if moved a lot.
When did you buy the Archer AX50? Did the issue occur when you installed it, or it happens after working fine for months?
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After 3 days I could confirm. There is a BUG. The connection was fine until yesterday, then it dropped again to 100Mb today.
I checked the Negotiation Speed Setting and it was fine -> 1000 Mb. BUT the in the basic information the Negotation Speed was indicating 100Mb.
I reboot the AX50, without change ANYTHING. And DONE! Negotiation speed in the basic information screen was back to 1000Mb.
See all the 3 screenshots attached (1-how it was, 2-parameter setting, 3-after reboot without any change).
Again, I didnt change ANYTHING ! Just reboot.
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Notice that the link Speed here reads as 100 Mbps. This means that the negotiated connection speed between the Ethernet adapter and whatever device it is plugged into is 100 Mbps. ... The only setting that is of concern for a Gigabit connection is that the adapter is set to Auto Negotiation.
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