Is 0:0:0:0:0:0:0:1 the loopback address for IPv6?

• A. True
• B. False
• C. Not a valid IPv6 address
• D. Depends on the operating system

Answer: (A)

In IPv6, the loopback address is ::1, which is the shorthand for eight 16-bit groups where the first seven are zero and the last is 1. The address 0:0:0:0:0:0:0:1 is exactly that full representation, and it's a valid IPv6 address that refers to the host itself. Because IPv6 allows zero compression, ::1 and 0:0:0:0:0:0:0:1 are the same address, used to test and route to the local machine. This behavior is defined by the IPv6 standard and isn’t dependent on the operating system. So, the statement is true.