Identify the four valid IPv6 addresses. (Choose four.)
A.
::
B.
::192:168:0:1
C.
2000::
D.
2001:3452:4952:2837::
E.
2002:c0a8:101::42
F.
2003: deaD. beef:4dad:23:46:bB. 101
Explanation:
IPv6 addresses are normally written as eight groups of four hexadecimal digits, where each group
is separated by a colon (:). For example, 2001:0db8:85a3:0000:0000:8a2e:0370:7334 is a valid
IPv6 address. To shorten the writing and presentation of addresses, several simplifications to the
notation are permitted.
Any leading zeros in a group may be omitted; thus, the given example becomes
2001:db8:85a3:0:0:8a2e:370:7334 One or any number of consecutive groups of 0 value may be
replaced with two colons (::): 2001:db8:85a3::8a2e:370:7334
This substitution with double-colon may be performed only once in an address, because multiple
occurrences would lead to ambiguity. For example, the illegal address notation 2001::FFD3::57ab,could represent
2001:0:0:0:0:FFD3:0:57ab
2001:0:0:0:FFD3:0:0:57ab
2001:0:0:FFD3:0:0:0:57ab and
2001:0:FFD3:0:0:0:0:57ab
Using the double-colon reduction the localhost (loopback) address, fully written as
0000:0000:0000:0000:0000:0000:0000:0001, may be reduced to ::1 and the undetermined IPv6
address (zero value), i.e., all bits are zero, is simply ::.
For example, the addresses below are all valid and equivalent:
2001:0db8:0000:0000:0000:0000:1428:57ab
2001:0db8:0000:0000:0000::1428:57ab
2001:0db8:0:0:0:0:1428:57ab
2001:0db8:0:0::1428:57ab
2001:0db8::1428:57ab
2001:db8::1428:57ab