Windows 10: View ipv6 subnet mask / prefix on Windows 10/11

I was looking for the IPv6 subnet mask / prefix on my Windows 11 installation. However ipconfig /all only shows complete IPv4 configuration, but IPv6 lacks this.In Article: https://answers.microsoft.com/en-us/windows/forum/all/fetch-ipv6-subnet-maskprefix-in-windows-10/62b8ecab-3e63-46cc-a6d3-01fddb9270da I found the same question, however I cannot reply to this as I found a quick solution/workaround by not useing ipconfig/all but netstat -rn.netstat -rn shows all routing table entries including IPv6 with subnet mask / prefix.Soi this is not really a question but more a workaround.Cheers!

:)

 

Fetch IPv6 subnet mask/prefix in Windows 10

Hi everyone!

With IPv4 I have succeeded in setting the configuration manually. However I have a problem in doing the same for IPv6: No matter if I look inside ipconfig or the Wifi settings, Windows won't show me the used subnet mask/prefix.

However, if I want to set it manually, I have to enter a subnet prefix, otherwise it won't save the settings.

I have just tried out random values. However the window still does not let me save the settings. Important suggestion for the future: Don't just display on the top that "something" is wrong and I have to edit the values again. Say exactly what is wrong.

Yes, I've already found the other community post about that topic, however the linked article only explains how to calculate the value if I want to create a new network. I know that from my computer science studies. But here, I have to find out the EXISTING subnet prefix that is used right now in my network. How can I find out that one?

 

Fetch IPv6 subnet mask/prefix in Windows 10

No, it can't be calculated based on an IP address. An IP address has no inherent information stored what the subnet mask is. That's why that information has to be stored additionally. That's why you ask me to provide that information when I am trying to set my IP address manually, if you could fetch it/calculate it from the IP address alone, you would not require that information.

Again, I have to remind you that I am trying to fix network issues in an existing network where I have no access to the router. This is not a professional environment actually, it is a student home and setting the IPv4 addresses manually has fixed some problems that we had. Now I need a solution to get to the IPv6 prefix, without having access to router settings, or how that home network inside our flat has initally been designed.

I know that the OS has to have that information, since it needs to operate with it. However, for some reason, the full IPv4 information is shown, but not the IPv6 information.

I already know how you would calculate the subnet prefix if you design a new network, having the number of hosts you want in that subnet. I've done that many times on paper for my exams. That is not the situation. I am in an existing network without any information how it was designed, and only need to get to that number that is already being used.

 

Fetch IPv6 subnet mask/prefix in Windows 10

Hi HadronFive,

Welcome to the Microsoft Community.



I understand that you'd like to know about the Fetch IPv6 subnet mask. It needs to be calculated based on the IP address.

• This article | Chapter 4 - Subnetting | Microsoft Docs may help.
  

• Also, it is advised that you post your issue on our IT Pro docs.microsoft.com. This community caters to IT professionals who can provide advanced explanations for your concern. You can click Q&A to post your question.
  

Feel free to reach back if you need further assistance.



Best regards

| Lynn Sun Microsoft Community Support Specialist

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