Plesk Subdomain with www Fix

Add one line to the special configuration file for the subdomain.

Normally this file is located in /srv/vhosts/yourdomain/subdomains/yoursubdomain/conf/vhost.conf .

If you do not see the vhost.conf file then go ahead and create it with the following text:
ServerAlias www.yoursubdomain.yourdomain.com

If you do not have write permissions, you will probably have to do this work via SSH.

What does ServerAlias www.yoursubdomain.yourdomain.com mean?

This is a Apache configuation that says that Apache will also serve the subdomain if you access it with www. This is normally used for the domain name, but also working for sub-domains.

If your www.yoursubdomain.yourdomain.com is not accessible please follow the next steps:

1. Add a record type in the DNS zone of the domain for the subdomain starting with www. Select the following menu entries:
   Server => Domains => yourdomain.com => DNS Settings
2. There you'll see a list of DNS entries for the domain. Check the IP address for the subdomain entry - copy to clipboard or write it down for reference (you will need it a minute!)
3. Now you create a new entry with the button Add new entry - use the following values:
   
   • Record type: A
   • Domain name: www.yoursubdomain
   • IP address: enter the IP address that you copied in step 2, e.g. 123.123.123.123
     
   Press OK to add the new entry to the DNS.

4. Check if there is a new entry wit the following value:
   www.yoursubdomain.yourdomain.com A 123.123.123.123

Recreate the Plesk / Apache configuration for the whole domain via SSH:

Restart Apache to read the new configuration and serve pages with www.yoursubdomain.yourdomain.com via SSH: