# /usr/local/nagios/libexec/check_ssh --help
check_ssh v2.0.3 (nagios-plugins 2.0.3)
Copyright (c) 1999 Remi Paulmier <remi@sinfomic.fr>
Copyright (c) 2000-2014 Nagios Plugin Development Team
	<devel@nagios-plugins.org>
Try to connect to an SSH server at specified server and port
Usage:
check_ssh  [-4|-6] [-t <timeout>] [-r <remote version>] [-p <port>] <host>
Options:
 -h, --help
    Print detailed help screen
 -V, --version
    Print version information
 --extra-opts=[section][@file]
    Read options from an ini file. See
    https://www.nagios-plugins.org/doc/extra-opts.html
    for usage and examples.
 -H, --hostname=ADDRESS
    Host name, IP Address, or unix socket (must be an absolute path)
 -p, --port=INTEGER
    Port number (default: 22)
 -4, --use-ipv4
    Use IPv4 connection
 -6, --use-ipv6
    Use IPv6 connection
 -t, --timeout=INTEGER
    Seconds before connection times out (default: 10)
 -r, --remote-version=STRING
    Warn if string doesn't match expected server version (ex: OpenSSH_3.9p1)
 -P, --remote-protocol=STRING
    Warn if protocol doesn't match expected protocol version (ex: 2.0)
 -v, --verbose
    Show details for command-line debugging (Nagios may truncate output)
Example)
define service {
        use                             generic-service,srv-pnp
        host_name                       compute1
        service_description             SSH
        check_command                   check_ssh!-p!5134
        notifications_enabled           0
        }