Which of the following is NOT a type of IP address?

Shared is not a recognized type of IP address in the context of standard classifications for IP addresses. The commonly accepted types include public, private, and loopback addresses.

Public IP addresses are assigned to devices that are directly accessible over the internet. These are unique across the entire internet and allow for communication outside of local networks.

Private IP addresses are used within local networks and are not routable on the internet. They are meant for internal communication between devices on the same network, which helps conserve the limited pool of public IP addresses.

Loopback addresses, typically represented as 127.0.0.1 in IPv4, are used for network testing and communication within the same device. When a device sends data to this address, it loops back to itself, allowing for self-testing of network applications.

The concept of a "shared" IP address does exist in certain contexts, like when multiple devices are behind a single public IP address through techniques such as Network Address Translation (NAT), but it does not qualify as an independent type of IP address according to the standard classifications used in networking.