Which statement is true about IPv6 address length?

• A. 32-bit
• B. 128-bit
• C. 64-bit
• D. 256-bit

Answer: (B)

IPv6 addresses are 128 bits long, providing a vastly larger address space than IPv4’s 32-bit length. This larger size was designed to accommodate the explosion of devices and to enable more flexible routing and hierarchical addressing. An IPv6 address is typically written as eight groups of four hexadecimal digits separated by colons, with rules to omit leading zeros and to compress consecutive zero groups.

In practice, many IPv6 deployments use a 64-bit network prefix and a 64-bit interface identifier, which supports automatic address configuration and efficient routing. Knowing the total address length is essential for understanding how IPv6 scales and how subnets are planned.

The 32-bit option is associated with IPv4, not IPv6. The 64-bit figure is a common portion of an IPv6 address (the interface identifier or sometimes part of the prefix) but does not represent the full address length. The 256-bit option is not used for IPv6 addresses.