IPv6 protocol defines an IP address of
- (a)32 bit
- (b)64 bit
- (c)128 bit
- (d)256 bit
Correct — C, 128 bit. IPv6 (Internet Protocol version 6) uses 128-bit addresses, giving about 3.4 × 10^38 unique addresses. It was designed to replace IPv4, whose 32-bit addresses (about 4.3 billion) were running out. An IPv6 address is written as eight groups of four hexadecimal digits separated by colons (e.g., 2001:0db8:85a3:0000:...).
- (a)32 bit — 32 bits is the IPv4 address length (about 4.3 billion addresses), not IPv6 — this is the classic trap.
- (b)64 bit — No IP version uses a 64-bit address; in IPv6, 64 bits is only the typical size of the interface/host portion, while the full address is 128 bits.
- (d)256 bit — No IP version defines a 256-bit address; it is a plausible-looking but incorrect figure.
An IP address uniquely identifies a device on a network. IPv4 uses 32-bit addresses written in dotted-decimal (e.g., 192.168.0.1). IPv6 uses 128-bit addresses written in colon-separated hexadecimal, and was created to overcome IPv4 address exhaustion.
This is straight recall — remember the pair: IPv4 = 32-bit, IPv6 = 128-bit. The jump is fourfold in bit length but astronomically larger in address space. The options 64 and 256 are plausible-looking traps.
- IPv6 address length = 128 bits (about 3.4 × 10^38 addresses).
- IPv4 address length = 32 bits (about 4.3 billion addresses).
- IPv6 is written as eight groups of four hexadecimal digits, colon-separated.
- IPv6 was developed mainly to solve IPv4 address exhaustion.
IPv6 quadruples the address length to 128 bits to escape IPv4 exhaustion — hence the answer is 128 bit (C).
- Choosing 32 bit — that is IPv4, not IPv6
- Confusing the 64-bit interface identifier with the full 128-bit IPv6 address
IT/computer sections ask 'IPv6 address is of how many bits' or 'IPv4 vs IPv6'. Lock 32-bit (IPv4) vs 128-bit (IPv6).
No directly related past PYQ was found.
- practice — not a real PYQ
An IPv4 address is how many bits long?
- (a)32
- (b)16
- (c)64
- (d)128
Answer(a) 32 bits — dotted-decimal, about 4.3 billion addresses.
- practice — not a real PYQ
IPv6 addresses are conventionally written in which notation?
- (a)Hexadecimal separated by colons
- (b)Dotted decimal
- (c)Binary octets
- (d)Base64
Answer(a) Hexadecimal separated by colons — eight groups of four hex digits.