OpenSSH SSH client (remote login program)

-2      Forces ssh to try protocol version 2 only.

-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

-c cipher_spec
        Selects the cipher specification for encrypting the session.

        Protocol version 1 allows specification of a single cipher.  The supported values are “3des”,
        “blowfish”, and “des”.  3des (triple-des) is an encrypt-decrypt-encrypt triple with three different
        keys.  It is believed to be secure.  blowfish is a fast block cipher; it appears very secure and is
        much faster than 3des.  des is only supported in the ssh client for interoperability with legacy
        protocol 1 implementations that do not support the 3des cipher.  Its use is strongly discouraged
        due to cryptographic weaknesses.  The default is “3des”.

        For protocol version 2, cipher_spec is a comma-separated list of ciphers listed in order of
        preference.  See the Ciphers keyword in ssh_config(5) for more information.

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.