In IPv6, an address is given by eight 16-bit numbers usually written in hexadecimal. As printed, how many unique addresses does IPv6 support overall?

An IPv6 address uses eight 16-bit groups, giving 128 bits in total and 2 to the power 128 possible unique addresses.

Each 16-bit group on its own can hold 2 to the power 16, which is 65536 values.

Counting only one group's 2 to the power 16 vastly undercounts the whole address space.

The figure 65536 describes a single group, not the entire IPv6 range.

Eight groups of 16 bits multiply together to give the full 128-bit space.

IPv6 was created precisely because IPv4's 2 to the power 32 addresses were too few.