What is the IPv6 address ::1 commonly known as?

The IPv6 address ::1 is known as the IPv6 loopback address. This address is used to refer to the local host, allowing a device to send packets to itself for various testing and troubleshooting purposes. Essentially, it is similar to the IPv4 loopback address 127.0.0.1.

When a device uses the loopback address, it bypasses the network interface and routes the data internally, which is useful for developers and network administrators to verify that the local networking stack is functioning correctly without involving external network components. In practical usage, if an application or network service is configured to listen on the loopback address, it will only respond to requests that originate from itself. This promotes isolation and is an essential feature for network diagnostics and service testing.