Recently, I have received a warning email from GitHub:
GitHub Pages recently underwent some improvements (https://github.com/blog/1715-faster-more-awesome-github-pages) to make your site faster and more awesome, but we’ve noticed that realguess.net isn’t properly configured to take advantage of these new features. While your site will continue to work just fine, updating your domain’s configuration offers some additional speed and performance benefits. Instructions on updating your site’s IP address can be found at https://help.github.com/articles/setting-up-a-custom-domain-with-github-pages#step-2-configure-dns-records, and of course, you can always get in touch with a human at [email protected]. For the more technical minded folks who want to skip the help docs: your site’s DNS records are pointed to a deprecated IP address.
- Pages are served via CDN (Content Delivery Network)
- DoS (Denial of Service) protection
But my site wasn’t properly configured to take advantage of speed and performance due to that the “DNS records are pointed to a deprecated IP address”.
What are the IP addresses that GitHub Pages uses before but have been deprecated now?
realguess.net is an custom zone apex domain (also called bare, naked, or root domain). The domain
blog.realguess.net is not a zone apex domain, but a subdomain. “A custom subdomain will not be affected by changes in the underlying IP addresses of GitHub’s servers.”  But, I am not using a subdomain. I have configured the zone apex domain to point to currently deprecated IP addresses. “If you are using an A record that points to 18.104.22.168 or 22.214.171.124, you will need to update your DNS settings, as we no longer serve Pages directly from those servers.”  So, these IP addresses are deprecated, and need to update the current DNS from:
to the new ones pointed by
And the new IP address are:
Using a subdomain is a better solution, so I don’t need to care about the changing GitHub Pages IP addresses in the future. But I don’t think the frequency of IP address updating is going to be very often. So, I will stick with my zone apex domain.