Change port / Relaunch ssh / Set XAuth in Mac OS Catalina

1. Change port accordingly: 

 port: sudo vi /private/etc/ssh/sshd_config
 ssh: sudo vi /etc/services

2. Relaunch ssh

 sudo launchctl unload /System/Library/LaunchDaemons/ssh.plist
 sudo launchctl load -w /System/Library/LaunchDaemons/ssh.plist

3. Check the port 

 ssh localhost -p ###port.number.here###

4. add XAuthLocation

For the client, modify .ssh/config as follows, 

     XAuthLocation ###your.xauth.path###

For the server, modify /private/etc/ssh/sshd_config and /etc/ssh/sshd_config

     XAuthLocation ###your.xauth.path###

, where you can check the path of xauth by following command: 

     which xauth