Which statement about IPv6 zero compression is true?

Which statement about IPv6 zero compression is true?

• A. It allows removing leading zeros in each hextet and can replace consecutive zero hextets with :: at most once in an address.
• B. It compresses the address to a 32-bit value.
• C. It changes the network prefix.
• D. It eliminates the need for a subnet mask.

Answer: (A)

IPv6 zero compression shortens the address by two simple tricks: you can drop leading zeros within each 16-bit group, and you can replace one run of consecutive zero groups with a double colon (::). The double colon may appear only once in an address to avoid ambiguity about how many groups were collapsed. This combination makes the textual form much shorter without changing the address’s value. For example, 2001:0db8:0000:0000:0000:ff00:0042:8329 can be written as 2001:db8::ff00:42:8329, using both techniques. This is why the statement is the true description of IPv6 zero compression. It does not reduce the address to a 32-bit value (that would be IPv4), it does not alter the network prefix, and it does not remove the need for a prefix length to define the network portion (the address is still paired with a prefix like /64 to indicate the network).

IPv6 zero compression shortens the address by two simple tricks: you can drop leading zeros within each 16-bit group, and you can replace one run of consecutive zero groups with a double colon (::). The double colon may appear only once in an address to avoid ambiguity about how many groups were collapsed. This combination makes the textual form much shorter without changing the address’s value. For example, 2001:0db8:0000:0000:0000:ff00:0042:8329 can be written as 2001:db8::ff00:42:8329, using both techniques.

This is why the statement is the true description of IPv6 zero compression. It does not reduce the address to a 32-bit value (that would be IPv4), it does not alter the network prefix, and it does not remove the need for a prefix length to define the network portion (the address is still paired with a prefix like /64 to indicate the network).