Reading and parsing IP address from config file should be changed as well. If an existing code base entirely relied on BSD socket interface such as inet_aton or inet_addr, it would be easier. However, if the code has proprietary parsing/converting functions, every incident should be found and changed. -Zach mentioned that security and authentication code mangled with IPv4. +Zach mentioned that security and authentication code mangled with IPv4.(IpVerifier) IPv6 address string is far longer than IPv4 address. IPv6 address [0001:0002:0003:0004:0005:0006:0007:0008], length is 41. IPv4 address 101.202.103.203, length is 15. About 3 times longer.
