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 tempering with my company's voting system. I was thinking of using a database to keep track of the IP addresses.

Update: Sorry about not being clear in the first time aruond. What i wanted to know if limiting 1 vote per IP address was a good strategy to limiting 1 vote per person. Basically, i wanted to know if 1 unique IP address is roughly equal to 1 person. People have already mentioned that proxies and routers re-use ip addresses so unfortunately, many people can be using the same ip address.

Thanks. I think, for my case, it'll be best to NOT limit 1 vote per ip address.

Answer 1

I would suggest not going with the IP approach. When I looked at this before some of your large ISPs reuse IPs a lot (AOL...), but if you do use IP addresses, use a database to track them. A fast way to do it is to make it a unique key and to catch the exception as "already voted".

One good thing to add is not to show a user that their vote was not counted, just show the results, or thank them for voting. By not giving that specific error, it is harder and sometimes not even noticed by your problem users.

Answer 2

If you use IP addresses then you'll be limiting most companies to only one vote because they route all outbound internet traffic through a firewall or proxy server. We did this a couple of years ago and found that all AOL traffic came from only 5 ip addresses.