Question

I’m trying to make a ASP.NET (C#) poll that will ask a user a Yes/No question and log that vote to the database. To prevent spam I would like to be able to make sure users can only vote once. I’ve thought about logging the users IP address. If this is the answer can someone give me a tutorial that shows how this can be accomplished. If this is not the answer then give me your suggestions.

Edit: I’m not asking users to register as this is not my website.

Answer 1

Logged in sessions are the only way to prevent double-voting fraud but since you explicitly ask for a way to log the IP address, you can get at that through:

HttpContext.Current.Request.UserHostAddress;

or

HttpContext.Current.Request.ServerVariables['REMOTE_ADDR'];

Should be easy enough to save to DB and check if IP already exists on each poll.