IPv6 address length – UGC NET Question

IPv6 was introduced to provide a vastly larger address space than IPv4, and it does this by using 128 bit addresses. These are typically written as eight groups of hexadecimal numbers separated by colons. The large number of possible addresses supports future growth of the internet and new types of devices. Hence, the blank should be filled with 128 bits.

Option A:
Option A, 32, repeats the IPv4 length and would not solve the problem of limited address space, which is the key motivation for IPv6.

Option B:
Option B is correct because formal specifications state that IPv6 addresses are 128 bits long, enabling an enormous number of unique identifiers.

Option C:
Option C, 64, would increase the address space but is not the standard length defined for IPv6.

Option D:
Option D, 256, is larger than necessary and does not match the protocol definition used in practice.