Subdomains and security with regards to root domain
 

Hi:
I'm hoping to get a confirmation from the security gurus that my thinking is correct. I'm looking to set up a subdomain such as test.mydomain.com from my main domain (mydomain.com) using a A record in the DNS. So the subdomain will in fact be hosted on a different server. The reason for this is because I'll be putting up some PHP scripts that have not been thoroughly tested yet for security, so in case the PHP scripts are exploited, the hacker can atmost only affect the subdomain.

Is my thinking correct on this as far as full isolation between the subdomain and main domain as far as security when the former is hosted on a separate server using A record? I mean, the two domains should basically be on two separate servers in every since of the word.

Thanks,

Yes, you should be fine because you aren't setting up a subdomain. :D A subdomain would mean you own bar.com and you are relegating oo.bar.com to someone else to create f.oo.bar.com, g.oo.bar.com, etc. By creating foo.bar.com, you are simply creating the host foo in the domain bar.com. At any rate, a compromise of this host doesn't neccesarily mean a compromise of the entire domain, assuming that you don't have sensitive info like usernames and passwords for bar.com stored somewhere on foo. ;)