Is there a way to non-interactively test to see if a server is connectable via SSH?

Question

I have a list of servers, and I'd like to see if each server is connectable via SSH to every other server. Looking at ssh's man page, I don't see an option to "SSH ping" a host to see if it is connectable, other than actually directly connecting manually and seeing if I get a password prompt.

Is there any way to automate this process that I'm not aware of?

Answer 1

You could use something like nmap to see if port 22 is open:

$ nmap -p22 192.168.1.0/24

That will report all machines on the specified subnet with port 22 open.