How to create a subdomain names with Github Page and default Gitpage domain name

Question

. 。 Answers to this question are eligible for a +50 reputation bounty. Danhui Xu wants to to this question: 这个问题：

give me a correct way to solve the Question plz !!!

I have a GitHub account called example and created a Gitpage called example.github.io .

Now I want to have a subdomain name with the example.github.io called sub.example.github.io that can access to example.github.io/sub .

I've searched a lot on the inte.net but almost every of them are about "how to use subdomain names with gitpage and custom domain", but I want to know how to create the subdomain names with default gitpage domain name like example.github.io and not with the custom domain.

I even tried to change the CNAME file (depends on some blog on the inte.net) but it never works.

Notice: this question is not smilar with this one , this question about how to use subdomain name with Gitpage and custom domain name .

Answer 1

github prohibits to use such subdomains:

 You cannot use custom domains ending with github.io, github.com, github.net, github.page, or githubusercontent.com.

So you can use either example.github.io/sub, or your own custom domain