DNS Server is pointing to wrong IP Address for a website

Hello All,

Our school uses OS X Server (Yosemite) to run a DNS server.

We recently switched a hosted website over to a new host. Publicly, everyone has been able to access the new site without issue. For some reason, all of the computers on our network point to the old IP address. I went into the OS X Server DNS settings and found that there was a "record" pointing to the old IP Address. I deleted the record, but for some reason it's still pointing to that IP.

I've tried flushing the DNS on a few computers, but it's still pinging the old IP address.

Any thoughts?

Thanks,

Max