Search and compare list of ever-growing IPs
I'm doing this at work. I use INET_ATON() to IPv4 and INET6_ATON() to IPv6. This search is faster than VARCHAR fields search. But, one important point:

This function was added in MySQL 5.6.3.
INET_ATON()   Return the numeric value of an IP address.
INET_NTOA()   Return the IP address from a numeric value.
INET6_ATON()  Return the numeric value of an IPv6 address.
INET6_NTOA()  Return the IPv6 address from a numeric value.

Documentation: MySQL Misc