Screened ip address can be edited, deleted, and changed to allow or block.

lib/validators/ip_address_format_validator.rb

@@ -0,0 +1,11 @@
+# Allows unique IP address (10.0.1.20), and IP addresses with a mask (10.0.0.0/8).
+# Useful when storing in a Postgresql inet column.
+class IpAddressFormatValidator < ActiveModel::EachValidator
+
+  def validate_each(record, attribute, value)
+    unless record.ip_address.nil? or record.ip_address.split('/').first =~ Resolv::AddressRegex
+      record.errors.add(attribute, :invalid)
+    end
+  end
+
+end