On Mon, Jan 07, 2019 at 10:13:03AM -0600, Tom Browder wrote: > I would like to use a single server for multiple remote services > including mail, bind dns, OpenStreep tiles, etcs., all with different > subdomain names but sharing the same server and IP. For example: > > mail.example.com > ns1.example.com > tiles.example.com > ... > > I know I can define them with individual A records (with the same IP) > with my domain host provider, but will that cause problems conflicting > with a single physical hostname of, say, "pluto.example2.net"? > > In other words, is the physical hostname of any server of any > importance except for logged in users?
The actual hostname as set in /etc/hostname does not have to match any of the various DNS A records, although it will save you some Sanity points if it does. The primary purpose of the actual hostname is for you to be able to identify *which* computer is having a problem. E.g. if you receive an email from a machine identifying itself as "www.yourdomain" but you have three such web servers operating as a round robin, then you will have to put in some work to figure out which of the three it came from. But if the email comes from a machine which self-identifies as "www1.yourdomain", then you have a better idea where to fix the issue.