I was studying for cisco exam and there is question if this address is valid IPv6 or not
an IPv6 address is made of 128 bits and it is represented using exadecimal digits.
Each hex digits represents 4 binary digits = 1 hex = 4 bits
So an IPv6 address is made of 128/4 = 32 hexadecimal digits
the usual hex dotted representation groups 4 hex and separate these groups using a ':'
So an IPv6 address is made of 8 4hex groups divided by :
the notation allows to represent one of more 4 hex consecutive groups made of all zeroes with a ::
This can appear only once in the number.
In your case the proposed hexadecimal sequence is:
Here we see only 6 4-hex groups, no :: appears in the middle to represent all zero groups so it is too short.
an IPv6 prefix is represented with a final ::/prefix length
this is not a valid IPv6 address because it is too short, it could be an IPv6 prefix if written as:
Hope to help