Find the IPv6 Equivalent of the IPv4 Loopback Address 127.0.0.1

A

In IPv6 the loopback address is written as,

This is a 128bit number, with the first 127 bits being '0' and the 128th bit being '1'. It's just a single address, so could also be written as ::1/128.

The IPv4 loopback address 127.0.0.1 is used to test network connectivity on the local host. IPv6 also has a loopback address, represented by the IPv6 address ::1. Therefore, the correct answer to the given question is A. ::1.

Let's break down the other options to better understand why they are incorrect:

B. :: - This represents the unspecified address in IPv6, which is equivalent to 0.0.0.0 in IPv4. It is not the same as the loopback address.

C. 2000::/3 - This represents a range of IPv6 addresses, not a specific address. It includes addresses that begin with the binary value 001, which is not related to the loopback address.

D. 0::/10 - This represents a range of IPv6 addresses, not a specific address. It includes addresses that begin with the binary value 0000000000, which is not related to the loopback address.

In summary, the correct answer to the given question is A. ::1, which is the equivalent of the IPv4 interface loopback address 127.0.0.1.