Can't Access website externally

I'm at a complete loss right now. I recently moved website domain name to new IP address (let's say us.com). The DNS working fine, which I had been told by system admin. I can access internally. As long as I connect external network. The website is not working. I requested to open port for 80 , 443 for my website. Another thing is, my old Ip address still works. If I type in Old Ipaddress, I can access internally and externally. Please help !