Limit 1 vote per IP Address?

Question

What I really want is to limit 1 vote per person but the next best thing i can think of is limit 1 vote per IP address to prevent malicious users/hackers from severely tempe

Answer 1

The way I have always done it is to concat the user agent and ip address into an MD5 hash (in some cases this will allow people from the same IP to vote, long as they are using different browsers), and store that as a "fingerprint" for the vote the the database and add a unique key to it. As IPX Ares said, from there you can catch the duplicate key exception, and you should be good.

If you wanted to allow people to vote once a day, you could also append the Ymd to that "fingerprint", or other variations to allow x amount an hour or x amount per day.