[edited based on information from later post]
DNS will not normally match the local server IP - in this case it does.
But it's an unnecessary lookup when the IP should always be the local one.
Apache doesn't ask the server what is his IP it asks DNS; which may be completely external to this system and an unnecessary point of potential failure.
Basically yes. Unless your server has multiple IPs all request are going to one IP already.
It just says "I'm here and listening on this IP and port for this servername" - which must match a real local IP and port that it is LISTENing on.
You do need to read up on implementing SNI.
Here is an abbreviated snip from a single working Apache conf file where 41 domains exist on a single IP:
And yes they all also work flawlessly
1 is http only
7 are https only
and 33 are both - with simple redirects:
RewriteEngine On
RewriteCond %{HTTPS} !=on
RewriteRule ^/?(.*) https://%{SERVER_NAME}/$1 [R,L]
<VirtualHost *:80>
ServerName 1.tld
<VirtualHost *:443>
ServerName 2.tld
...
<VirtualHost *:443>
ServerName 8.tld
<VirtualHost *:80 *:443>
ServerName 9.tld
...
<VirtualHost *:80 *:443>
ServerName 41.tld
until we find every conf file in use (like the one with the _default_ ) you won't be able to fix the problem completely.
Look for "NameVirtualHost" in the conf
You will only get part of it to work and only by accident.
Because it is not doing what you are telling it to do.
Apache is getting mixed signals.
Those vhost files are being ignored and only one was being used as an unmatched fallback
Which Apache will continue to do after the vhost names really don't match (but they already don't match - you just think they do).