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What Is MTU Size and What Value Should It Be Set To in 2022?

MTU Size

About the MTU Size

If you are reading this article, we are assuming that you have a wifi connection at home that you use to access the Internet. Well, connecting the router to the power cable to access the internet is possibly the easiest way to go about it. However, did you know that you are missing out on your router’s best internet speed because you don’t know what MTU is and how it can streamline your wireless connectivity experience?

Well, MTU is the maximum packet size that can be transmitted over the router. Knowing the ideal MTU size and then changing it to the router’s needs can help in several ways than you know of. Not only does it reduce the risks of lagging speed, but it also reflects well on the complaints about disconnections and other network complications that you might be experiencing.

If you aren’t sure what MTU is, we will be highlighting the same in detail, what it entails and how you can consider changing it in the long run. Let us highlight the same for you.

What is MTU?

MTU translates to Maximum Transmission Unit and is a particular setting that is available in your router. It is an adjustable setting that you can change and adjust to further optimize the overall speed of your router. As we mentioned before, knowing about the MTU allows you to know the maximum packet size that can be transmitted over the specific network that you are working with.

The same is measured in bytes and determines the efficacy of the physical network interface. There is no standard when it comes to the MTU and typically varies depending on the type of router or the network that you are using. 

Typically, the MTU size for the Ethernet is around 1500 bytes. It can be more or less dependent on the connectivity and the network involved in the equation. In case the messages that are transmitted across the network are larger than the MTU size of the network you are using, it will be broken down into smaller packets and then transmitted accordingly.

When is the Right Time to Change the MTU?

Since the concept of MTU is quite less known and not everyone is familiar with it, it isn’t surprising that many individuals aren’t even aware of when the right time to change the MTU is. If you are one of those people, we are here to clarify your doubts or lack of knowledge surrounding the same.

If you are experiencing delays and lags in the network speed, knowing about the MTU size is the first step to correcting the issue. When you contact the router company that you have, ideally, the first step of troubleshooting is by knowing and understanding the MTU size of the network. Checking the MTU size is also crucial if the user is experiencing any kind of performance-related issues with the network.

However, if you are worried that it is going to be a very complicated process, that isn’t the case. All you will need is a computer and a router. There is no additional hardware or software needed for the same.

Once you know the MTU size, it becomes easier for you to decide whether the issue is with the MTU size or any other network-related issues in the device. Typically, the larger the MTU size, the easier it becomes for you to fit more data into fewer packets for faster transmission.

However, in case of any errors during the data transmission process, the packet will prolong the transfer by first rectifying the issue that has occurred in between. The MTU size is also directly correlated with the improved latency of the data packets that you are dealing with.

So, if you are tired of the consistent lags and delays in your network, know the standard MTU size of your router and then fix it accordingly for your best usage. Knowing this can help with the performance optimization of the router in a matter of minutes. And, spending this time will ensure that you don’t have to complain about the usage of the network in the long run.

How Can You Find the Ideal MTU Size?

When it comes to determining the MTU size, there are several ways you can go about it. We’d recommend that you stick to the standard model of testing, which is the PING TEST.

In this, the user has to send multiple consecutive ping requests and then reduce the packet size gradually. You need to do this till the packet size doesn’t need any further fragmentation. The ping command has to be run under the Command prompt, so having a basic idea about the same is expected if you wish to check the MTU size of your router or the network that you are using.

However, we understand that not everyone will know all the steps to the Ping test. So, we have sorted that out for you in detail. 

Accessing Command Prompt in Windows

cmd in windows
  • Start by opening your laptop or desktop.
  • Press down the Windows key + R key to open the Run window
  • Under that, type cmd and then click on OK
  • This will open the Command Prompt window

Accessing Command Prompt in Mac

spotlight in mac
  • Start by opening your Macbook
  • Press down on Command + Spacebar to open Spotlight
  • Under that, type terminal and then press Enter
  • This will open the Terminal window, which is similar to the Command prompt that you have for Windows.
terminal window in mac

Now that you know how to open the Command prompt on Windows and Mac, let us teach you how to run the Ping tests. Knowing this can solve a lot of your complaints when it comes to the network speed and the constant lags that you are experiencing while accessing the internet.

Here’s what you need to do:

  • Once you are on the Command prompt window, go ahead and follow the steps
  • Type in the pingable domain and follow it up with -f and -l switches. End that with the packet size
  • Once you run the command, check if the message says that the packets need to be fermented further or not. Run the test again. But, this time, reduce the packet size by 10-12 bytes.
  • Do this until you reach a packet size that doesn’t need any further fragmentation.
  • Once done, you then need to do the opposite and gradually increase the packet size. Don’t go too overboard and increase it in smaller graduations. You need to do this till you reach the largest packet size.
  • From there, take the optimal packet size that you have gained and then add 28 to it. The reason why you need 28 bytes is that 20 correspond to the IP header and 8 corresponds to the ICMP Echo Request header.

Once you add 28, that is your optimal MTU size of the router or the network that you are using.

How to Change the MTU Size?

Now that you know how to find the optimal MTU size, the next thing you need to know is the changing process. How should you change it? Typically, the change can be made directly from the router or even from your connected laptop or desktop’s settings. You need to find the option that works the best for you. 

Using a Router

If you have a router that allows changing the MTU size, we’d recommend that you contact the company or check out the process on the official website. It is very subjective and the steps involved are quite elaborate that will depend on the individual settings, hardware and software of the router that you are using. So, get in touch with the individual company and then get going with the process.

Using Your Computer

The process of changing the MTU size from the router directly can be a little tedious and require technical and hardware knowledge. If you don’t want to get into a process, we’d recommend that you use the other hack, which is using your computer settings.

Let us elaborate a bit of that with the steps mentioned down below:

  • As an Administrator, open the Command Prompt window on your computer as we said before
  • Once the window opens, type in the following command “netsh interface ipv4 show subinterfaces”. Once done, press Enter.
  • This will open up the interface and give you an insight into the MTU sizes. Keep a note of the interface that your computer is using. It could be Ethernet, most commonly.
  • Once you have made notes follow it up with the command, “netsh int ipv4 set subinterface “Your Interface” mtu=1428 store=persistent”. Press on Enter.
  • This will change your MTU size. Once done, close the window.

This is an extremely simple yet lucrative process to optimize your network speed and network settings without any complications.

Conclusion

If you are confused about MTU, we hope this article gives you all the basic insights you need to know about. Knowing the MTU size can help you out in the long run. So, if you weren’t familiar with this, it is time that you change that.

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