antirez/redis — pull request #1156 by charsyam (2013-06-15 02:41:29+00:00)
Title: change REDIS_IP_STR_LEN to 48 bytes for IPv6 string address

Considering IPv6(because redis will support IPv6 also)

IPv6 string address can represent to 45 bytes.

ref: http://stackoverflow.com/questions/166132/maximum-length-of-the-textual-representation-of-an-ipv6-address