SSH warning: untrusted X11 forwarding setup failed:

Warning: untrusted X11 forwarding setup failed: xauth key data not generated.
Warning: No xauth data; using fake authentication data for X11 forwarding.

solution:- 

# vim /etc/ssh/ssh_config

Host *

        CheckHostIP             no

        ForwardX11              yes

        ForwardX11Trusted       yes      <-- Add this line

        ForwardAgent            yes

        StrictHostKeyChecking   no

        UsePrivilegedPort       no

        Protocol                2,1

        HostbasedAuthentication yes

        EnableSSHKeySign        yes

:wq (save and exit)

# service sshd restart