Default handling for unmatched domains/subdomains in Apache

Question

I have an Apache2 configuration with multiple VirtualHosts. My DNS is set to accept *.<domain>.<tld> on multiple domains. Everything is working correctly but if I go to something-random-here.example.com I seem to get an invalid VirtualHost being selected (I am guessing the first or last one it finds). Is there a way to tell Apache to use certain rules if none of the VirtualHost entries match the domain or subdomain? I'd preferably like to return a 404.

Answer 1

Apache uses the first virtualhost if no name matches. Just configure a new virtualhost as the first one with a random name, displaying whatever you like - or returning a 404 page.

Answer 2

Wildcard include your site configuration files:

Include path/to/site/confs/*httpd.conf

Organize your site conf files so they are loaded in an expected order. Example...

01-httpd.conf

02-site1-httpd.conf

03-site2-httpd.conf

etc...

Apache will read these in order. Then create one that will always load last to catch any unmatched virtual hosts and return a 404 instead of loading a default site.

99-catchall-httpd.conf

<VirtualHost *:8080>
 ServerName null
 ServerAlias *
 Redirect 404 /
</VirtualHost>

<VirtualHost *:8443>
 ServerName null
 ServerAlias *
 Redirect 404 /
</VirtualHost>

Be sure to replace the ports with whatever ports your httpd listens on. Or if you have httpd listening on specific interfaces, you'll need to add a catchall for each interface instead, like so:

<VirtualHost 192.168.1.101:8080>
 ServerName null
 ServerAlias *
 Redirect 404 /
</VirtualHost>
<VirtualHost 192.168.1.101:8443>
 ServerName null
 ServerAlias *
 Redirect 404 /
</VirtualHost>

<VirtualHost 192.168.1.102:8080>
 ServerName null
 ServerAlias *
 Redirect 404 /
</VirtualHost>

<VirtualHost 192.168.1.102:8443>
 ServerName null
 ServerAlias *
 Redirect 404 /
</VirtualHost>

Hope this helps. I use this method to load sites in the order I specify and prevent unmatched virtual hosts from loading an unexpected site unintentionally.

Answer 3

As Moritz Both mentions, Apache2 will use the first virtual host it finds if it does not match any that you have requested.

When you first install Apache2 there's a default website conf that you can use as a template, modify or delete, and I was always wondering what the 000-default.conf was actually for, because they had a default.conf too. After reading what Moritz Both said, it all makes more sense now.

What I did for my server was copy the config for the default hostname (website) to 000-default.conf file and a2ensite 000-default.

Now, everytime there is an unmatched domain request to my website, it serves up the 000-default page, which is just a copy of my actual default page.