Advanced SSH Command Usage

1. Accessing SSH on non-standard ports for security

By default, SSH listens on port 22. However, to enhance security, you can configure SSH to listen on a non-standard port. To connect to an SSH server running on a non-standard port, you need to specify the port number using the -p option. For example, to connect to an SSH server running on port 2222, you would use the following command:

ssh -p 2222 username@hostname

Replace username with your username, hostname with the IP address or domain name of the SSH server, and 2222 with your desired non-standard port number.

2. SCP command and how to use it with custom ports

SCP (Secure Copy) is a command-line tool that allows secure file transfers between a local machine and a remote machine over SSH. It uses the same authentication and security mechanisms as SSH. To copy a file from the local machine to a remote machine on a custom port, use the following command:

scp -P 2222 /path/to/local/file username@hostname:/path/to/remote/directory

To copy a file from a remote machine on a custom port to the local machine, use the following command:

scp -P 2222 username@hostname:/path/to/remote/file /path/to/local/directory

Replace username with your username, hostname with the IP address or domain name of the remote machine, 2222 with the custom port number, and provide the appropriate file paths.

3. X forwarding with custom ports

X forwarding allows you to run graphical applications on a remote machine and have the application windows displayed on your local machine. To enable X forwarding with a custom SSH port, you need to use the -X option and specify the port number using the -p option when connecting with SSH. For example:

ssh -X -p 2222 username@hostname

Once connected, you can run graphical applications on the remote machine, and they will be displayed on your local machine. Make sure you have an X server installed and running on your local machine for X forwarding to work.

4. Link to ssh man page

For a comprehensive and detailed reference on the SSH command and its various options, you can refer to the SSH manual page. It provides information about the available options, configuration files, and other related topics.