are github`s IP Addresses changed?

Solution 1:

alex.forencich's comment on your question probably explains what you're seeing.

The A records for github.com may be different depending on where you're asking from. Keep in mind the "you" in the previous sentence really refers to whatever recursive DNS server your server's resolver is talking to. Your ISP's DNS server answers with IPs in AWS's eu-central-1 Availability Zone, which is in Frankfurt, Germany -- totally reasonable since your ISP is Hetzner.

I don't know Google's public recursive DNS servers work, but the answers you get when you ask there seem to be ones intended for North America.

Coming back to the reason you asked in the first place, if for some reason you need to know the IPs your internal hosts are going to be talking to, you'll need to look at what they use for their DNS servers, and use the same servers to grab the IPs for use on your firewall rules. There isn't a single "real" answer, so what you should be aiming for is consistency.

Solution 2:

If you must rely on IP addresses, and I can sympathize with your comment, you should refresh them regularly. GitHub publishes the IP addresses they use on https://api.github.com/meta

Solution 3:

Don't rely on IP addresses (it's not the '60s), they will change anytime the server changes provider, or implements a CDN, or a mirror, or a set of load balancers. Domain names are less likely to change.

And they don't have to notify anyone if they do anything on the backend, they can just mirror the infrastructure, change providers and change the domain records. Business as usual. This is trivial and sysadmins around the world are doing this all the time.