Setting The MTU In Windows Vista

Long ago, when I first heard of the dynamic tuning in the Windows Vista TCP/IP stack, I envisioned the manual setting of the static MTU to be a thing of the past. Unfortunately, I was wrong - the MTU is still a fixed setting, in Vista.

The legendary tool, DrTCP, which is used by everybody to change the MTU in Windows 2000 and XP, doesn't work under Windows Vista. Fortunately, Microsoft now allows us to adjust the MTU using the "netsh" command. As other commands in Windows Vista, you run "netsh" using the command window, in Administrative mode.

To see what interfaces you have on your computer, type

netsh interface ipv4 show subinterfaces

To change the MTU, type
netsh interface ipv4 set subinterface "Local Area Connection" mtu=nnnn store=persistent

Local Area Connection is the name of the network connection on your computer, from the list obtained above.
nnnn is the desired value for MTU.

Reboot after making the change.

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Felipe said...

helpful. thank you. Works in W7 beta too.

nate.m said...

you do not know how much this helped me out. i was about to reinstall my os (win7) out of desperation. thanks bro

Rahul said...

this definitely helps and works in all version of vista and above. No more external tools required!
Thanks mate..

Zachary Sunberg said...

Awesome. Thanks so much. Works in Windows 7... you don't even need to reboot!

Unknown said...

wow. this has saved me. thank you so much. i tried just about everything.

schmegle said...

this was really helpful, thank you. I had problems browsing any site but Google. Changed the MTU to 1492 (from 1500) and solved the problem right away. No need to reboot or reset services in Win7

Naveed said...

Great post. I have been trying to fix mtu, as I was unable to view quite a few websites after upgrading my Internet connection to Fiber. Changing mtu to under 1500 resolved the issue. As stated in earlier comments, no need to reboot on Windows 7, just use store=persistent to make sure it is saved permanently on your machine.

Bunni said...

You are Awesome...It perfectly solved my problem...Thanks alot for the post...

Joanna's Blog said...

Thanks for this but I'm still having problems when typing in these entries in CMD even if I'm running as administrator. I tried to type in netsh interface ipv4 set subinterface "Local Area Connection" mtu=1492 store=persistent and it said Element not found.

I'm connecting to the internet using my laptop in Windows 7 and the connection is wireless. We're using ZyXel modem/router for this as well.

Please help.


PS. Haven't had any connection problems for several months and just recently I'm experiencing slow downloads, cannot buffer well on Youtube (for even 2min videos) and slow uploads. I'm thinking if this can resolve the problem (altering MTU)

Also my Samsung laptop is relatively new and I haven't changed so much of its default settings yet so I don't think it's a problem of the unit but please let me know if there are other options.