We do not respect rules 3 and 4 in the required list:
1. omit leading zeros
2. "::" used to their maximum extent whenever possible
3. "::" used where shortens address the most
4. "::" used in the former part in case of a tie breaker
5. do not shorten one 16 bit 0 field
6. use lower case
http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-04.html
Submitted by: Kalluru Abhiram @ Juniper Networks
Obtained from: Juniper Networks
Reviewed by: hrs, dougb