parameter 'SSHLocation',
            :Description => 'The IP address range that can be used to SSH to the EC2 instances',
            :Type => 'String',
            :MinLength => '9',
            :MaxLength => '18',
            :Default => '0.0.0.0/0',
            :AllowedPattern => '(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})/(\\d{1,2})',
            :ConstraintDescription => 'must be a valid IP CIDR range of the form x.x.x.x/x.'