Cox High Speed Internet IP addresses are dynamically assigned to each computer on the Cox High Speed Internet network. Therefore, an IP address can change at any time. If you need static IP addressing, please contact Cox Business Services for a business solution that fits your needs.
Feedback received on this FAQ entry:
you want dynamic ip address because this will prevent more viruses/computer attacks in the future
I'm not sure about COX in other areas, but in the Hampton Roads area, COX HSI uses a DHCP scheme where DHCP is used to provide a static address which is provisioned based on the MAC address; It is very, very rare for your IP to change, and tends to happen only under rare unknown circumstances or replacement of hardware, such as the cable modem or router. In almost 10 years, my IP has changed only twice. Pretty good for DHCP. It would seem that COX uses a static allocation scheme but provides it via DHCP for ease of configuration on the user end (as DHCP provides the user with a very simple plug-and-go setup of their computer or router).