The double-double



What does a double-colon designate in an IPv6 address?

A) The separation of the host and subnet

B) The end of the address

C) Abbreviation of two or more groups of zeros

D) The beginning of the address

E) The part of the address where your eyes glaze over at all of the hexadecimal numbers


The answer: C) Abbreviation of two or more groups of zeros

If an IPv6 address has two or more groups of zeros, the entire group can be replaced with a pair of colons. Only one range of zeros in an IP address can be abbreviated with the double-colon designation.

Want to know more? Watch “IPv4 and IPv6.”

Although IPv4 has been the most popular protocol in the world, IPv6 has now become a standard installation in Windows 7. In this video, you’ll learn how to identify IPv4 addresses and IPv6 addresses, and how IPv6 addresses can be abbreviated to save space and make them more readable.