How to Change the MTU on a Netgear Router

What MTU is

MTU stands for maximum transmission unit. It is the largest packet of data, in bytes, that your connection sends in one piece. If packets are larger than a link along the way allows, they are broken up or dropped, which can slow things down or cause certain sites or apps to fail.

Should you change it?

In most cases, no. The default value works for most connections, and changing MTU rarely makes a speed test faster. Consider a change if:

• Some websites will not load although others do
• Video calls, VPNs or online games fail or lag in odd ways (for call-quality problems on internet phone services, see VoIP not working on Wi-Fi)
• Your provider specifically tells you to use a certain value
• You use a connection type such as PPPoE that needs a smaller value

If you are chasing general slowness, start with the steps in our Netgear slow-internet guide first.

Common MTU values

• 1500 is the usual default for standard Ethernet connections.
• 1492 is commonly used for PPPoE connections, which some DSL and fiber providers use.
• 1480 and 1400 are sometimes suggested for particular setups, such as tunnels, but they are not universal improvements.

There is no single best number. A lower MTU means more, smaller packets, so lowering it without a reason can slightly reduce efficiency. For gaming, a lower value is not generally proven to help. The right value is the largest one that works reliably on your connection.

Find your best MTU with a ping test

On Windows, open Command Prompt and run a ping with the do-not-fragment flag. Start at 1472, which gives an MTU of 1500 once headers are added:

ping google.com -f -l 1472

If you see a message that the packet needs to be fragmented, lower the number by 10 and try again. When it replies normally, note that size, and add 28 to get your MTU. For example, a working payload of 1464 means an MTU of 1492. On macOS the command uses different flags, so check its manual page for the right ones.

Run this test over a wired connection if you can, since Wi-Fi can add noise.

Change the MTU on a Netgear router

Menu names vary by model and firmware, so the steps below may look slightly different on your router.

1. Connect a computer to the router by Wi-Fi or Ethernet.
2. Open a browser and go to routerlogin.net, or the router’s IP address, such as 192.168.1.1.
3. Enter your router’s admin username and password. If you never changed them, check the label on the router or Netgear’s documentation, or see where to find your router password and login. The Nighthawk app may also be used on some models.
4. Go to Advanced, then Setup, then WAN Setup.
5. Find the MTU Size field. Enter your chosen value. Some models only show the field for certain connection types.
6. Click Apply and wait for the router to restart its connection.
7. Test the connection and the apps or sites that were failing.

If the setting is missing on your model, check the user manual. Some routers hide it or only show it for certain connection types.

How to check the MTU in the router

The same WAN Setup page shows the current MTU value. On a computer, you can also check the interface MTU. In Windows, use netsh interface ipv4 show subinterfaces in Command Prompt.

If things get worse

Change back to the previous value, usually 1500, and restart the router. Change only one thing at a time, and write down the value you started with. If problems continue, restart the modem and router, then contact your provider, who can confirm the MTU that your connection needs.

Related checks

MTU is one setting among many. For a broader view of what limits your speed, see does your router or modem affect internet speed.