def METHOD_NAME(self):
    """Exits with an error if the hostname
    does not conform to expected format"""
    # Input Validation - Rock my regex ;-)
    re_hostname = re.compile(r"^[a-zA-Z0-9]+[a-zA-Z0-9-]*((([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,6})?$")
    re_ipaddr = re.compile(r"^((25[0-5]|2[0-4]\d|[01]\d\d|\d?\d)\.){3}(25[0-5]|2[0-4]\d|[01]\d\d|\d?\d)$")
    if self.server is None:
        end(UNKNOWN, "You must supply a server hostname or ip address. " \
                   + "See --help for details")
    if not re_hostname.match(self.server) and \
       not re_ipaddr.match(self.server):
        end(UNKNOWN, "Server given does not appear to be a valid " \
                   + "hostname or ip address")