validates_ip_format_of 
Rails plugin that provides a validates_ip_format_of method to ActiveRecord models. IPs are validated by regexp.
Support
Tests are run on all versions listed.
Rubies
1.9.21.9.3head
ActiveRecord
~> 3.0.0~> 3.1.0~> 3.2.0master
Usage
After installing the plugin, it's used like
class User < ActiveRecord::Base
validates_ip_format_of :dhcp,
:allow_nil => true,
:message => 'is completely unacceptable'
end
Takes the same arguments as validates_format_of except for the :with regexp.
Please note that the regexp used to validate IPs is not perfect, but hopefully good enough. See the test suite. Patches are very welcome.
Limitations and design choices
Does not handle IPv6.
By design, the plugin does not allow RFC 1918 IPv4 addresses, e.g., 10.0.0.0, 172.16.0.0, 192.168.0.0, from being input. Also, prevents 127.0.0.1 and 0.0.0.0.
Credits and license
Based on my contributions made to validates_url_format_of written by Henrik Nyh, which is also released under the MIT license.
See LICENSE.md