Q:

Ruby on Rails - Restricting click by IP

I am new to rails so go easy. I have created a blog with the ability to "vote" on a post by using a feature much like Facebook's "like". I am not using any authentication but would like to restrict voting on a particular post by IP. That is, once someone votes for a post, they cannot vote again (unless they reset their router of course). 
I feel like this should be something I affect by modifying the votes or posts Model, but I fear it has to do with Sessions, which...I don't have any experience yet. 
Let me know if you need me to post any code. Here is the votes controller.
class VotesController < ApplicationController

  def create
    @post = Post.find(params[:post_id])
    @vote = @post.votes.create!(params[:vote])

       respond_to do |format|
       format.html { redirect_to @post}
       format.js
     end
  end
end

A:

Two ways of doing it come to mind right away, there are probably others. Both require storing an IP in the database.

Block the vote from being created with a uniqueness validation.
class Vote < ActiveRecord::Base
  validates_uniqueness_of :ip_address
  ...
end

Block the vote from being created in the controller
class VotesConroller < ApplicationController
  ...
  def create
    unless Vote.find_by_post_id_and_ip_address(params[:post_id],request.remote_ip)
       posts.votes.create!(params[:vote].update({:ip_address => request.remote_ip}))
    end
  end
end

