I have to admit the four tiniyints was my first idea but I realized the limitations imposed by that solution immediately, yes its human readable, so what, add the function to your select statement, problem solved.

I believe the binary(4) solution also has merit. I would be curious how it stacks up against the others, since it is just a cast operation and no math.

When the four octets are stored in a single field you are able to do IN operations or much cleaner (and I'm sure faster) correlated sub-queries.

I just see more options with a single column solution and will not be particularly worried about what NF it fits it. Human readability is not a major concern in the DB, if that was then we would never store ID values for a customer id, we would store all the customer information in the table with the order and I think we can agree that is NOT a good solution. Human readability can be achieved with minimal effort if necessary.

Also, as with any problem there is more than one solution, the four tinyints may be just fine for your app, but I know that the next time I need to store IP addresses this article will come to mind..

CEWII