Some times we required to validate IP address of system through Regex, then this example is the solution for your requirement, See the example:
public bool IsValidateIP(string Address)
{
//Match pattern for IP address
string Pattern = @"^([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}$";
//Regular Expression object
Regex check = new Regex(Pattern);
//check to make sure an ip address was provided
if (string.IsNullOrEmpty(Address))
//returns false if IP is not provided
return false;
else
//Matching the pattern
return check.IsMatch(Address, 0);
}