Changing the MTU size in Windows 10

I recently bought an Alienware with a great graphic card (Geforce gtx 1060) which I was planning on using to do some 3D rendering. While trying to project what I was doing using Chromecast I ran into a really specific issue, after a couple of seconds the image was frozen but the audio was still there. So, I searched everywhere but it was really hard to find a real solution. So, one of the best solutions I found was that I had to reduce the MTU (maximum transmission unit) to help solve the casting issue.  This problem originates when a computer is trying to transmit or receive some data through the internet which results in slow speeds or interrupted access to some sites or casting using your WiFi. Changing the MTU size can help resolve these problems.

The following tutorial will show you how to do it:

  • Open CMD (Command Prompt) in administrator mode:
    • Search for CMD
    • Right click over CMD and choose the option: run as administrator
    • You will get a windows asking: Do you want to allow this app to make changes to this device? Windows Command Processor : Yes – No:
      • Press Yes and you will get black pop up window.

Once the Command Prompt window is open you will have access to change the MTU settings following these steps:

  • Type netsh interface ipv4 show subinterface and press enter. You will see a list of network interfaces.

  • Type:
    • netsh interface ipv4 set subinterface “Local Area Connection” mtu=1458 store=persistent.
    • Replace “Local Area Connection” with the name that appeared in the “Interface” column. In my case, the name is Wi-Fi but it could be Wireless Network Connection or something else and press Enter.
  • Restart your computer and then test again. If it doesn’t work try decreasing the MTU to 1450 or 1448. Don’t go below 1400.  
  • If you want, you can ping google to check if your packages are being fragmented. Type ping -f -l 1458.