Connecting a local linux computer over public ip using ssh command

Question

I want to turn my raspberry pi 3 model B into a public server (only for testing purposes not production purposes). I have a second windows PC in which cygwin is available for linux commands such as:

ssh root@ipadress -p port 

When I try to connect my raspberry pi locally using putty with the local ip adress, I can reach raspberry pi's terminal over putty.

But I cannot connect raspberry pi with the 'ssh' command neither using local ip adress nor public ip adress.

Locally 'permission denied' warning appears, publicly 'connection refused' warning appears. What can be the source of my problem? - PS: I also cannot connect with putty using the public ip.

Answer 1

that's many problem in one.

first do not use -p portnumber as ssh will listen in port 22 (unless you have change it in /etc/ssh/sshd_config)

next, by default root login is disable in raspian, have you enabled it ?

To do so edit /etc/ssh/sshd_config, there is a line with PermitRootLogin, simply change no to yes, uncomment if need be, restart ssh (or reboot).

next, putty screenshot do not show which user connect, maybe pi ? if so try

ssh -l pi localip

finally, to access rapsberry from you public IP, you have to setup your modem to NAT (Network Address Translation) public IP to local IP for port 22. See your modem interface for this.