Which statement best describes a key difference between IPv4 and IPv6 addressing?

• A. IPv6 uses shorter addresses than IPv4.
• B. IPv6 provides a much larger address space and simplifies autoconfiguration, while IPv4 uses NAT to conserve addresses.
• C. IPv4 inherently supports global unicasting without NAT.
• D. IPv6 requires more devices to configure manually.

Answer: (B)

The main idea is how many addresses exist and how devices get their address. IPv4 uses 32-bit addresses, which caps the number of unique addresses and led to widespread use of NAT to share a single public address among many devices. IPv6, with 128-bit addresses, provides a vastly larger address space and includes built‑in autoconfiguration options (like SLAAC and DHCPv6) so devices can configure themselves with little or no manual setup. Because of that large address space and automatic configuration, NAT isn’t needed for IPv6 in most cases, unlike IPv4. The other statements aren’t correct: IPv6 addresses are not shorter, IPv4 can rely on NAT but isn’t required to guarantee global unicasting, and IPv6 doesn’t require more manual configuration due to its autoconfiguration features.