How To Change MTU Size In Windows 7

By default, the MTU (Maximum Transmission Unit) size is 1500. I’ve run into issues pulling up resources in remote regions, such as South Africa, where MTU restrictions are implemented by local ISP’s. To work around these obstacles, changing the MTU size is necessary.

To begin, ensure you’re an admin user on the computer. These instructions are assuming you are using your Local Area Connection for your connection which is most likely a Cat5 cable.

1. Open a command line window as an Administrator (ie. right click on All Programs > Accessories > Command Prompt and select Run as administrator)
2. Type the command netsh and wait for prompt
3. Type the command interface and wait for prompt
4. Type the command ipv4 and wait for prompt
5. Type the command set subinterface “Wireless Network Connection” mtu=1300

Leave the command prompt up so you can change it back to 1500 when you are done. There are troubleshooting steps to take to see if you are having an MTU size issue that I will cover in another post. Come back and search regularly.

Open Command Prompt As An Administrator In Windows

This post describes how to open a command prompt with full administrator permissions in the following Windows Operating Sytems:

Windows 7, Windows Essential Business Server, Windows SBS 2003, Windows SBS 2008, Windows Server 2000, Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2, Windows Server 2008, Windows Server 2008 R2, Windows Vista

 

To open a command prompt as an administrator,

1. Click Start, click All Programs, and then click Accessories.
2. Right-click Command prompt, and then click Run as administrator.

If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.