How to connect to a SSH server from Android client? I can install and run an SSH server on my Android 6.0 phone (Banana SSH server), and I can run an SSH client on it (Termius), so how do I invoke the client from on the command line that the server provides?  I type ssh and it's not a recognized command.  I want to use the phone to link through to other servers.
You don't need to install server in order to use client. Install openssh package on Termux, that has both; server and client. To connect to a server, do: ssh &lt;user&gt;@&lt;server-IP&gt;. Mention port with -p option if different than default (22), such as Termux server uses 2222 8022 (corrected by @Steve).

Or if you want to stick to GUI, you can go for Termius or ConnectBot etc.

In order to run SSH server, just execute sshd from Termux, but that gets killed with app. Or for a more complicated setup see: How to run SSH/SFTP server for multiple user logins with password authentication on Android?