Machine A is connected to the internet and is behind firewall so it cannot receive incoming connections. Machine B is open to the internet.
I want to be able to type commands into B and have them execute on A. Except it is A that has to reach out to B to establish the connection before B can send it commands.
Can this be done running SSHd on A and plain SSH client on B or do I need a combination of SSHd and SSH client on A (client to establish reverse tunnel pointing to SSHd).