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?
You should use a Regular Expression
Regular Expression
Here is one that does what you want:
/^([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}$/.match("#{@systemIP}")