How can I make Apache return error on wrong http_host? [duplicate]

Question

I need to return an error on wrong http_host header. For nginx I would write the following config:

server { 
    ## Deny illegal Host headers
    if ($host !~* ^(mydomain.com|www.mydomain.com)$ ) {
        return 444;
    }

    location  / {
        proxy_pass               http://app_server;
        ...
    }
}

How can I do the same for Apache?

UPDATE

Although the trick with virtualhosts does work, I ended up with RewriteRule:

RewriteEngine On
RewriteCond %{HTTP_HOST} !^(www\.)?example\.com$ [NC]
RewriteRule ^(.*)$ - [L,R=400]

Answer 1

here is an example

<VirtualHost _default_:80>
    ErrorDocument 403 /403.html
    ErrorDocument 404 /404.html
</VirtualHost>

just don't put ServerName or ServerAlias inside of this VirtualHost.

Answer 2

Just make a VirtualHost that matches whatever host header you're interested in and then return whatever error you want.