Which IP version uses 128-bit addresses?

Which IP version uses 128-bit addresses?

• A. IPv4
• B. IPv6
• C. Both
• D. Neither

Answer: (B)

Address length differentiates IP versions. IPv4 uses 32-bit addresses, which limits the total number of unique addresses to about 4.3 billion and is usually written in dotted decimal form. IPv6 uses 128-bit addresses, written in hexadecimal and separated by colons, which expands the address space to about 3.4 × 10^38 possibilities and supports features like automatic address configuration and more efficient routing. Because the question specifies 128-bit addresses, IPv6 is the version that fits this requirement, while IPv4 does not.

Address length differentiates IP versions. IPv4 uses 32-bit addresses, which limits the total number of unique addresses to about 4.3 billion and is usually written in dotted decimal form. IPv6 uses 128-bit addresses, written in hexadecimal and separated by colons, which expands the address space to about 3.4 × 10^38 possibilities and supports features like automatic address configuration and more efficient routing. Because the question specifies 128-bit addresses, IPv6 is the version that fits this requirement, while IPv4 does not.