If you are using cPanel and wish to set dedicated IP to your subdomain, you will find no else where to do that.
However, this could still be able to fix as this article.
– You have domain domain.com and subdomain blog.domain.com.
– You wish to set dedicated IP for blog.domain.com which originally 100.100.100.100 and result as blog.domain.com resolve to 10.0.0.1.
1. Log into SSH, go to the folder of /var/cpanel/userdata,
2. Select the cPanel username folder such as mickgenie.
3. You will now see the following file,
4. Open the file named blog.domain.com,
5. You should find the content as below,
6. Change it to detail as below,
7. Now, you have done but you will need to rebuilt the Apache,
8. Restart the Apache services,