Ssh (OpenSSH client)

ssh^[1] is the OpenSSH ssh client for logging or executing commands into remote devices/machines

     ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface] [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]
        [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11] [-i identity_file] [-J destination] [-L address]
        [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port] [-Q query_option] [-R address] [-S ctl_path]
        [-W host:port] [-w local_tun[:remote_tun]] destination [command]

-X Enables X11 forwarding

ssh -V
ssh -t

Windows: Settings > Apps and click “Manage optional features” under Apps & features.

Configuration

Configuration file: ~/.ssh/config

Usage

ssh REMOTE_USERNAME@REMOTE_SERVER_NAME_OR_IP
ssh -vvv REMOTE_USERNAME@REMOTE_SERVER_NAME_OR_IP (-v increase verbosity, maximum 3)
- ssh -vvv REMOTE_USERNAME@REMOTE_SERVER_NAME_OR_IP 2>&1 | grep "STRING_TO_SEARCH"

Execute a remote command:

ssh USERNAME@SERVER_NAME '/path/to/remote/scripts/backup.sh'

ssh -Q kex SERVER

Example commands

ssh -o StrictHostKeyChecking=accept-new [email protected] (since OpenSSH 7.5, March 2017)
ssh -o StrictHostKeyChecking=no [email protected]^[2]
ssh -Q kex SERVER
ssh -o MACs=hmac-sha2-256 HOSTNAME

Multiplexing options

ssh -O check server.example.org or ssh -O check [email protected] 
Master running (pid=26289)

ssh -O check [email protected] 
Control socket connect(/path/): No such file or directory

To stop an specific multiplexed session:

ssh -O stop [email protected]

Avoid using Multiplexing for a connections:

ssh -o "ControlMaster=no" server.example.org

Logs

ssh -i id_ed25519_xxxxx.pub SERVER_NAME
Load key "id_ed25519_xxxxx.pub": invalid format
Solution:
Use private key instead of public key ^[3]
ssh -i id_ed25519_xxxxx SERVER_NAME