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.

Here are some examples about how you could do …

As a long-time registrar, we are aware of the importance of keeping up with the internet, as well as trying to be at the forefront of changing technologies as we have done for the past four years. Now it's time to do the same with IPv6!

As a result of this and requests from our customers coupled with the ominous depletion of IPv4 address space, I am pleased to announce that we will be offering IPv6 connectivity for our customers.  Given that IPv6 is the future of the Internet, it is perfectly logical that it is something of particular interest to us.  

This is, of course, not an overnight affair, and will take some time to be able to fully offer the service for all customers, and at the moment we expect to pass through several stages of testing before general deployment.   In any case, we hope to have IPv6 fully available for our customers before the end of the year.

What is the …