`/etc/ssh/ssh_config` is not code but rather a configuration file used...

/etc/ssh/ssh_config is not code but rather a configuration file used by the OpenSSH client. It specifies default settings for SSH client connections on a Linux or Unix-based system.

When the SSH client (ssh) is invoked, it reads this file to determine global options for connecting to remote servers. Some examples of settings in this configuration file include:

• Default settings for connecting to SSH servers, like:
  • The protocol version to use (Protocol 2).
  • The port to connect to (Port 22).
  • The preferred cipher algorithms or key exchange methods.
• Custom behaviors for specific hosts, using Host blocks to define server-specific settings.
• IdentityFile to specify which private key files to use for authentication.
• Forwarding settings (e.g., ForwardX11 or ForwardAgent).
• Time-out configurations like ServerAliveInterval or ConnectTimeout.

This file provides system-wide defaults, and individual users can override these by defining their own settings in ~/.ssh/config.