I've been having trouble with one of my linux computers. I have a router and two linux boxes behind it. I want to access both of them from Internet with ssh.
I have set up port forwarding: port 2220 goes to machine A:22, port 2221 goes to machine B:22. I know the public IP of the router and can ping/connect to it either using the public IP or my set up DDNS service.
I can ssh from machine A to B through local net fine. I can ssh to machine A from Internet.
Here's the problem: I cannot ssh into machine B from Internet. The connection just times out.
When connecting I am using the -p flag to select the port (the connection Internet->A works fine)
Machine A: Ubuntu 16
Machine B: RaspberryPi 3 running Minibian headlessly. Doesn't seem to have iptables or ufw installed.
Any help greatly appreciated.