Working with IP addresses

Hey all, I find myself in need of working with IP addresses. However, the situation is a bit strange. There will be a form with a text box to allow IP address entries as follows: 192.168.5.195 or 123.23.35.4 123.23.35.45 123.23.35.74 or 123.4.34.1/123.4.34.255 or 13.234.5.41/13.234.5.75 12.34.34.150/12.34.34.225 The above a just a few examples. I need to be able to grab either the IP addresses or the ranges and verify that when an IP is entered at a later date and compared to the above types of previously saved data that the IP is within the range(s). I hope I explained that ok. ;) So basically I guess I just need a way of, after retrieving the info from the DB, splitting the IP (range(s)) apart and then comparing the IP entered to those in the array(?) to verify that it was a good entry. Thanks for any help. I'm gonna to rest my brain a bit now. chuck