For MySQL it's a best practice to store IP addresses in a INT column rather than in a VARCHAR. This allows for more compact storage. This best practice is only for MySQL as PostgreSQL does have data types like inet and cidr.
MySQL is equiped with the INET_ATON() and INET_NTOA() functions since version 3.23.15. In MySQL 5.6.3 the INET6_ATON() and INET6_NTOA() functions were addes to finaly add IPv6 address support. To make it easier to work with IPv4 and IPv6 addresses the IS_IPV4_COMPAT(), IS_IPV4_MAPPED(), IS_IPV4() and IS_IPV6() functions were added. The difference between the new and old functions is that the old functions use INT UNSIGNED to store IP addresses and the new function uses VARBINARY(16) for IPv6 addresses and VARBINARY(4) for IPv4 addresses. [Read more...]
