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

The Rails way to validate with ActiveRecord in Rails 3 is:

@ip_regex = /^([1-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3}$/

validates :gateway, 
          :presence => true, 
          :uniqueness => true,
          :format => { :with => @ip_regex } 

Good resource here: Wayback Archive - Email validation in Ruby On Rails 3 or Active model without regexp