def long()
			words = []
			7.downto(0) do |x|
				word = (@addr >> 16*x) & 0xffff 
				words.push( word.to_s(16).rjust(4, "0") )
			end
			return words.join(':')
		end
def long()
			words = []
			7.downto(0) do |x|
				word = (@addr >> 16*x) & 0xffff 
				words.push( word.to_s(16).rjust(4, "0") )
			end
			return words.join(':')
		end
long returns the IPv6 as a string in long (uncompressed) format