When you attempt to connect to your plug using SSH from an outside network, are you typing in your external IP address? For example, are you typing: "ssh username@XX.XX.XXX.XXX
" where XX.XX.XXX.XXX is the address of your modem or are you typing from the external network "ssh firstname.lastname@example.org
What error message are you getting? You said you can connect from your internal network without issue, correct? Can you ping your plug from the external network?