GL-AX1800 capped speed at 300MBPS?

Hi Everyone,

I’m encountering a vexing issue where my internet speed is systematically capped at 300 Mbps when using my GL-AX1800 router, regardless of it being through wired or WiFi connections. My actual plan is 600 Mbps, and I’ve approached multiple avenues to troubleshoot without success. Your insights or suggestions would be hugely valuable.


  • Internet Plan: 600 Mbps.
  • Direct Connection: 580 Mbps via Ethernet.
  • Through Router: Stuck at 300 Mbps, both wired & WiFi.
  • Devices: Using recent devices, inclusive of a WiFi 6 laptop and a phone utilizing 5G WiFi, all tests performed without VPN.
  • Router Support Feedback: Mentioned possible losses via the router, which doesn’t seem to fully explain the dramatic speed reduction.

Router Software Info:

  • OpenWrt Version: OpenWrt 21.02-SNAPSHOT r16399+159-c67509efd7
  • Kernel Version: 4.4.60

Troubleshooting Undertaken:

  • Router Firmware: Upgraded to the latest available version.
  • Cable Testing: Utilized various cables to ensure they’re not the cause.
  • Router Reset: Executed a full reset and tested with default settings.

It’s baffling that the speed is consistently capping at 300 Mbps through the router, despite its specifications and settings ostensibly supporting my 600 Mbps subscription comfortably. Have any of you encountered a similar situation or have any further troubleshooting steps to propose?

Thank you so much in advance for your assistance!

Hi, this is very strange, I can’t currently test this myself as i do not use GL firmware but a personal build of OpenWRT (Native) on both my Flints and Slate AX’s however what i would do is the following.

  • Drop the logs and post to forum (Helps us techie folk help you)
  • Check firmware for any QoS/SQM options and disable them
  • Install iperf3 on two systems and run a test

As you stated you have changed the cable and done the other steps such as Router firmware upgrade and router resets that will then leave the issue to hardware (includes the cable).

If your still stuck with 300Mbps after the above contact Gl-iNet for RMA

Do you use speedtest to test your speed?If yes, take note of the test node of speedtest.