The SSH connection to a remote system using LCOS‘s own SSH client is initiated from the CLI with the following command:
ssh [-(?|h)] [-(b|a) <Loopback-Address>] [-p <Port>] [-C] [-j <keepalive-interval>] [-l login_name] [-o "option=value"] [<User>@]<Host> <Command>
The individual parameters have the following meaning:
- -?, -h
- Displays a brief help text about the available parameters
- -b, -a <Loopback-Address>
- Allows a sender address (loopback address) to be specified. This option is especially important in connection with ARF: By entering an optional loopback address you change the source address and route used by the device to connect to the remote system. This can be useful, for example, when the system is available over different paths and it should use a specific path for its reply message.
- -p <Port>
- Specifies the port to be used. If you do not specify a port, the device reverts to the SSH standard TCP port 22.
- -C
- If you set this parameter, the SSH client uses the zlib algorithm to attempt to negotiate a method for data compression with the remote system. If the remote system does not support compression, then the data is transmitted uncompressed.
- The use of compression is generally worthwhile only for very slow connections. With fast connections, the performance loss from the additional overhead due to compression tends to be greater than the gain from reduced data amounts.
- -j <keepalive-Interval>
- If the connection to the remote system is routed via a NAT router or a firewall, it may be worthwhile to leave the connection running permanently. With an interactive SSH session, data is not transferred at all at certain phases, which can lead to disconnection because of timeouts. In such cases the SSH client can regularly transmit keep-alive packets, which are irrelevant to the remote system but which inform the gateway that the connection is still being used.
- Use this parameter to specify the interval in seconds in which your device sends the keep-alive packets. The keep-alive packets are only transmitted when the SSH client is not sending other data to the remote system.
- -o <option=value>
- Possible values:
-
- StrictHostKeyChecking=<yes|no|off|ask|accept-new>: enable/disable host key checking (default: ask)
- SignHostKeyAlgorithms=[+|-]<alg-list>: augment/reduce/set list of allowed signature algorithms
- VerifyHostKeyAlgorithms=[+|-]<alg-list>: augment/reduce/set list of accepted signature algorithms
- KeyAlgorithms=[+|-]<alg-list>: augment/reduce/set list of allowed key exchange algorithms
- Ciphers=[+|-]<alg-list>: augment/reduce/set list of allowed cipher algorithms
- MACs=[+|-]<alg-list>: augment/reduce/set list of allowed (H)MAC algorithms
- Password=<password>: set password (disables keyboard-interactive authentication method)
- <User>
- User name for logging in to the remote system. If you do not specify an explicit user name, LCOS uses your current username that you used to log in to the CLI.
- <Host>
- DNS name or IP address of the remote system.
- <Command>
- The LCOS SSH client either starts an interactive shell on the remote system or it executes a single command. If no command is entered, the interactive shell starts.
