I followed the Ubuntu 12.04 server setup as well as the Wordpress setup. Wordpress works fine. I then followed the multsite tutorial but am unable to get subdomains to load. When I visit a subdomain, it takes me to my internet providers page that says "Unable to find".
I am able to ping my main domain fine, but it times out if I try any subdomains.
It seems the wildcard entry for your domain is not set. Lets assume you have domain example.com, for which you have set A record to point to your server, but not for *.example.com so any subdomain like abc.example.com will not point to your server at all.
That was the problem. I was so caught up in setting up the server and wordpress configuration that setting an A record with a wildcard just completely slipped my mind.
Thanks, its working great now!
Welcome :)