I have a Debian Wheezy server with a domain name and a static ip address. The domain name's "A" record set to my server's ip address. Everything works fine. The problem started when another guy set my server's ip address under his own domain name as an "A" record, so when I put his domain name, my server appears. My question is how to prevent this, how to limit the server to one domain name? The dns server is not on the Debian server.
Thank you for your help!