regex - Rails 3: Validate IP String

Question

In Rails 3, is there a built in method for seeing if a string is a valid IP address?

If not, what is the easiest way to validate?

Answer 1

Just wanted to add that instead of writing your own pattern you can use the build in one Resolv::IPv4::Regex

require 'resolv'

validates :gateway, :presence => true, :uniqueness => true,
  :format => { :with => Resolv::IPv4::Regex }