Why is the fourth IPv6 address invalid?
Q) Which of the following IPv6 addresses is invalid?
[Q2bi 9608/11 Oct/Nov 2018]
According to the answer sheet, all the IP addresses are valid except the last.
I know that the first is standard IPv6 address with a "shortcut" of writing ":0001:" as just ":1:"
And the second is an Ipv4 address in IPV6 format
However I don't understand the last two. If I'm counting correctly, the third has only 12 bytes when "expanded" (59FB:0000:0000:1005:CC57:6571) but IPv6 addresses should have 16 bytes. While on the other hand the fourth does indeed have 16 bytes. If what I've said is correct, shouldn't the third be the invalid IP address while the fourth be the valid one? Instead of the other way round?
An explanation would be greatly appreciated!
Many thanks in advance.