We've been asked to create a special system for certain institutions to be recognised on a closed system by IP Address.

I'm just wondering what the best way would be to store an IP address range in the database so that I can easily get an institution id code from comparing the REMOTE_ADDR server variable against the stored range?

any ideas would be welcome

I haven't tried this, but maybe by taking out all the non-numbers and storing as a number? Computers are much faster at sifting through numbers than text. The key thing to making this successful would be ensuring that you stored 12.12.12.12 as 12012012012 so that entries are in proper numerical order.

EDIT: And, putting a UNIQUE index on the field.

I agree with Jeremy that you should store IPs as numbers rather than strings. Another approach, rather than just dropping the decimal and adding a zero where necessary, would be to convert an IP to its decimal numeric equivalent.

An IP address is just a series of four 8-bit binary numbers. Given the full, 8-bit representation of each value, you can drop the decimals and convert the resulting 32-bit binary number to decimal. If you are using PHP there are two functions which will simplify this process for you:

http://us.php.net/manual/en/function.ip2long.php
http://us.php.net/manual/en/function.long2ip.php