Summary
SSH clients are highly configurable through environment variables, command-line options, and keywords in configuration files. Remember that command-line options have the highest precedence, followed by your local client configuration file, and finally the global client configuration file.
Client configuration files consist of sections that apply to individual hosts or groups of hosts. When you run an SSH client, remember that multiple sections can apply to it, according to the precedence rules we covered. If the same keyword is set multiple times, the earliest (OpenSSH) or latest (Tectia) value is the winner.
When experimenting with client configuration, remember verbose mode. If you experience unusual SSH behavior, your first instinct should be to add the -v option and run the client again, watching the debug output for clues.
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