Which of the following is a correct IPv6 address example?

Which of the following is a correct IPv6 address example?

• A. 2001:0db8::1
• B. 192.168.0.1
• C. 10.0.0.1
• D. 127.0.0.1

Answer: (A)

IPv6 addresses are written with hex digits and colons, arranged in eight groups of four hex digits, and they can be shortened by omitting leading zeros or replacing consecutive zero groups with a double colon. The example 2001:0db8::1 uses this shorthand correctly: it has the initial groups 2001 and 0db8, then :: to compress the run of zeros, and ends with 1. Expanded, it becomes a full eight-group address, which is valid. The other options use dots and decimal numbers, which is how IPv4 addresses are written (four decimal octets separated by dots). Those are IPv4 formats, not IPv6.

IPv6 addresses are written with hex digits and colons, arranged in eight groups of four hex digits, and they can be shortened by omitting leading zeros or replacing consecutive zero groups with a double colon. The example 2001:0db8::1 uses this shorthand correctly: it has the initial groups 2001 and 0db8, then :: to compress the run of zeros, and ends with 1. Expanded, it becomes a full eight-group address, which is valid.

The other options use dots and decimal numbers, which is how IPv4 addresses are written (four decimal octets separated by dots). Those are IPv4 formats, not IPv6.