OpenSSH SSH client (remote login program)

-N      Do not execute a remote command.  This is useful for just forwarding ports (protocol version 2
        only).

-T      Disable pseudo-tty allocation.

-o option
        Can be used to give options in the format used in the configuration file.  This is useful for
        specifying options for which there is no separate command-line flag.  For full details of the
        options listed below, and their possible values, see ssh_config(5).

              AddressFamily
              BatchMode
              BindAddress
              ChallengeResponseAuthentication
              CheckHostIP
              Cipher
              Ciphers
              ClearAllForwardings
              Compression
              CompressionLevel
              ConnectionAttempts
              ConnectTimeout
              ControlMaster
              ControlPath
              DynamicForward
              EscapeChar
              ExitOnForwardFailure
              ForwardAgent
              ForwardX11
              ForwardX11Trusted
              GatewayPorts
              GlobalKnownHostsFile
              GSSAPIAuthentication
              GSSAPIDelegateCredentials
              HashKnownHosts
              Host
              HostbasedAuthentication
              HostKeyAlgorithms
              HostKeyAlias
              HostName
              IdentityFile
              IdentitiesOnly
              IPQoS
              KbdInteractiveDevices
              KexAlgorithms
              LocalCommand
              LocalForward
              LogLevel
              MACs
              NoHostAuthenticationForLocalhost
              NumberOfPasswordPrompts
              PasswordAuthentication
              PermitLocalCommand
              PKCS11Provider
              Port
              PreferredAuthentications
              Protocol
              ProxyCommand
              PubkeyAuthentication
              RekeyLimit
              RemoteForward
              RequestTTY
              RhostsRSAAuthentication
              RSAAuthentication
              SendEnv
              ServerAliveInterval
              ServerAliveCountMax
              StrictHostKeyChecking
              TCPKeepAlive
              Tunnel
              TunnelDevice
              UsePrivilegedPort
              User
              UserKnownHostsFile
              VerifyHostKeyDNS
              VisualHostKey
              XAuthLocation

-p port
        Port to connect to on the remote host.  This can be specified on a per-host basis in the
        configuration file.

-R [bind_address:]port:host:hostport
        Specifies that the given port on the remote (server) host is to be forwarded to the given host and
        port on the local side.  This works by allocating a socket to listen to port on the remote side,
        and whenever a connection is made to this port, the connection is forwarded over the secure
        channel, and a connection is made to host port hostport from the local machine.

        Port forwardings can also be specified in the configuration file.  Privileged ports can be
        forwarded only when logging in as root on the remote machine.  IPv6 addresses can be specified by
        enclosing the address in square braces.

        By default, the listening socket on the server will be bound to the loopback interface only.  This
        may be overridden by specifying a bind_address.  An empty bind_address, or the address ‘*’,
        indicates that the remote socket should listen on all interfaces.  Specifying a remote bind_address
        will only succeed if the server's GatewayPorts option is enabled (see sshd_config(5)).

        If the port argument is ‘0’, the listen port will be dynamically allocated on the server and
        reported to the client at run time.  When used together with -O forward the allocated port will be
        printed to the standard output.

-i identity_file
        Selects a file from which the identity (private key) for public key authentication is read.  The
        default is ~/.ssh/identity for protocol version 1, and ~/.ssh/id_dsa, ~/.ssh/id_ecdsa and
        ~/.ssh/id_rsa for protocol version 2.  Identity files may also be specified on a per-host basis in
        the configuration file.  It is possible to have multiple -i options (and multiple identities
        specified in configuration files).  ssh will also try to load certificate information from the
        filename obtained by appending -cert.pub to identity filenames.

ssh connects and logs into the specified hostname (with optional user name).  The user must prove his/her
identity to the remote machine using one of several methods depending on the protocol version used (see
below).

If command is specified, it is executed on the remote host instead of a login shell.