How to Change the MTU in Windows 7

A while ago I was having problems loading images from PhotoBucket. This was annoying since they are everywhere. The problem was reasonably easy to track down, though a bit mysterious. A maximum transmission unit (MTU) setting of anything other than 1500 will cause PhotoBucket images to fail. Strange, but changing the MTU has always been very easy. Well, easy unless you’re running Windows 7. Here’s how to fix it.

The first thing to do is verify what the MTU is currently set at. Open a command window (Start, type cmd, press enter).

In the command window enter the following (just copy and paste it):

netsh int ip show int

This will return something like this:

See the one that says 1500? That used to say 1498 (or something close, I don’t recall now). I don’t know why it was set lower than 1500 at the factory but it was.

The key here is to record the Idx number of the adapter that you need to change. In this case it’s Idx 13.

Then enter the following substituting your own Idx:

netsh interface ipv4 set subinterface “13” mtu=1500 store=persistent

Press enter and you should be good to go, no reboot. You can validate the setting took effect by entering the first command again.