Redirect all subdomains to main domain using .htaccess. Using some sort of a mass-hosting provider, you never know what they might change in your DNS automatically. This is a backup solution to make...
The Apache HTTP Server, colloquially called Apache, is the world's most used web server software. Apache played a key role in the initial growth of the World Wide Web as the dominant HTTP server, and has remained most popular since April 1996. Apache is developed and maintained by an open community of developers under the auspices of the Apache Software Foundation. Most commonly used on a Unix-like system (usually Linux).