What is the total number of unique IP addresses available under IPv6?

The total number of unique IP addresses available under IPv6 is an immense figure, specifically 340,282,366,920,938,463,463,374,607,431,768,211,456. This vast number results from the structure of IPv6, which uses 128-bit addresses. The significance of using 128 bits is that it allows for a staggering 2 raised to the power of 128 unique combinations of addresses.

Calculating this, we arrive at the formula:

2^128 = 340,282,366,920,938,463,463,374,607,431,768,211,456

This exponential growth in address space is a critical design feature of IPv6, as it was developed to replace the limited address space provided by IPv4, which provides around 4.3 billion addresses (2^32). The staggering number of unique addresses in IPv6 supports the rapidly growing number of devices connected to the Internet, ensuring that every device can have its own unique address without the risk of running out of available addresses.

The other options represent numbers that either fall short of the actual count of unique addresses in IPv6 or significantly overstate or misinterpret the number of available IPs