Understanding Round Robin DNS: A Study on Server Selection

A recent blog post by OpenFreeMap explores how browsers and CDNs select which server to use when multiple servers are configured behind a Round Robin DNS. The author, Hyperknot, delves into the inner workings of this DNS technique, comparing browser behaviors and sharing findings.

Key takeaways include:

* Browsers like Chrome and Firefox may choose a server randomly at first, but then stick with it unless re-evaluation after a few hours.
* Safari consistently selects the closest server, even if it goes offline temporarily.
* Curl and other command-line tools can be configured to prioritize servers based on ping times.
* Cloudflare's behavior is different from other browsers, as it sticks with its initial selection regardless of whether the server is online or not.

Source: https://blog.hyperknot.com/p/understanding-round-robin-dns