The loopback addresses (both in IPv4 and IPv6) is an address which represents the same interface of a computer. ... In IPv6, the IPv6 address reserved for loopback use is 0000:0000:0000:0000:0000:0000:0000:0001/128.

How do I set the loopback address in IPv6?

To configure an IPv6 address for the loopback interface, enter the ipv6 address <ip-address> command at the loopback interface configuration level, as shown in the following example. When you configure an IPv6 address for a loopback interface, you do not specify a prefix. The default prefix/128 applies automatically.

Why does IPv6 only have one loopback address?

IPv4 allocates a whole block of IPv4 loopback addresses, 127.0. 0.0/8 . IPv6, in contrast, only allocates a single loopback address, ::1 . This seems surprising that IPv6 would be so stingy in its allocation of loopback address(es), since overall it provides a huge increase in address space.