Small point of grammar: AD goes in front of the date. IPv6 will be exhausted in AD 5,395,000,000,000,000,000,000,000,000,000, not 5,395,000,000,000,000,000,000,000,000,000 AD.
Explanation: AD stands for anno Domini, "in the year of our Lord...." You would say "in the year of our Lord 2015," not "2015 in the year of our Lord."
Explanation: AD stands for anno Domini, "in the year of our Lord...." You would say "in the year of our Lord 2015," not "2015 in the year of our Lord."
BC and CE go after the date.