I got so fed up with debugging DNS issues on Linux I ended up writing this series of posts: https://zwischenzugs.com/2018/06/08/anatomy-of-a-linux-dns-lookup-p

I got so fed up with debugging DNS issues on Linux I ended up writing this series of posts: https://zwischenzugs.com/2018/06/08/anatomy-of-a-linux-dns-lookup-part-i/ https://zwischenzugs.com/2018/06/08/anatomy-of-a-linux-dns-l... https://zwischenzugs.com/2018/06/18/anatomy-of-a-linux-dns-lookup-part-ii/ https://zwischenzugs.com/2018/06/18/anatomy-of-a-linux-dns-l... https://zwischenzugs.com/2018/07/06/anatomy-of-a-linux-dns-lookup-part-iii/ https://zwischenzugs.com/2018/07/06/anatomy-of-a-linux-dns-l... https://zwischenzugs.com/2018/08/06/anatomy-of-a-linux-dns-lookup-part-iv/ https://zwischenzugs.com/2018/08/06/anatomy-of-a-linux-dns-l... and I haven't even covered caching.