These messages are common, especially for public internet connections where the SSH client does not have any control over its Reverse DNS Record.

How to solve.
Comment out the following line in /etc/hosts.deny.

#  ALL: PARANOID

The error ‘X11 forwarding request failed on channel 0’

1. Edit /etc/ssh/sshd_config by adding the following lines.

# Tanaka added following 4 lines to delete the error message. 2017/July/7
# X11 forwarding request failed on channel 0
#   "/usr/X11/bin/xauth" or "/opt/X11/bin/xauth"
#
X11Forwarding yes
XauthLocation /opt/X11/bin/xauth
XauthLocation /usr/X11R6/bin/xauth
X11DisplayOffset 10
X11UseLocalhost no

The command

ssh -Y owner@lp.harima.riken.jp

gives no warning, but, once this command described in a shell file, like

-rwxr-xr-x 1 owner staff 35 10 22 2015 ~/bin/lp 

has the following line

ssh -Y owner@lp.harima.riken.jp

then, this shell command gives

Warning: No xauth data; using fake authentication data for X11 forwarding.

This warning goes out if you add

XauthLocation /opt/X11/bin/xauth
XauthLocation /usr/X11R6/bin/xauth

in the file /etc/ssh/ssh_config.

• Debian: install xrdpvnc4server xbase-clients, vnc4server, and xbase-clients

 sudo apt-get install vnc4server xbase-clients xrdp

• Macos: install rdesktop

 sudo port install rdesktop

• connection example

 
rdesktop -u username -g 1600x1200 -k en-us servername