Question : Disallow access to certain websites

I currently disallow users access to websites, by editing the Hosts file on each workstation to redirect the site to 127.0.0.1. This works quite well, but I am seeking a more centralised approach.

I figured that I could create A Records for each site in DNS, and it would do the same thing. I find that once I create them, the correct ip address is resolved through nslookup but IE still takes me to the external site.

Can anyone explain why this is happening, and whether I am on the right or wrong track attmpting to use DNS

Answer : Disallow access to certain websites

I have resolved this myself through DNS.

I added an additional zone and added a host record called * (meaning everything in this zone) to be directed to 127.0.0.1.