X11 connection rejected because of wrong authentication.

xclock which is usually used to install some applications as GUI mode.

Below are the main packages which we have to install to work xclock

check with rpm command

# rpm -qa | grep -i xorg*

xorg-x11-drv-evdev-2.6.0-2.el6.x86_64
xorg-x11-utils-7.5-6.el6.x86_64
xorg-x11-font-utils-7.2-10.el6.x86_64
xorg-x11-xkb-utils-7.4-6.el6.x86_64
xorg-x11-server-common-1.10.6-1.el6.x86_64
xorg-x11-server-Xorg-1.10.6-1.el6.x86_64
xorg-x11-apps-7.6-6.el6.x86_64
xorg-x11-drv-ati-firmware-6.13.0-6.el6.noarch
xorg-x11-drv-vesa-2.3.0-2.0.1.el6.x86_64
xorg-x11-proto-devel-7.6-25.el6.noarch
xorg-x11-xauth-1.0.2-7.1.el6.x86_64
xorg-x11-fonts-misc-7.2-9.1.el6.noarch
xorg-x11-drv-void-1.4.0-1.el6.x86_64

>> check below config file is enlabled or not?       X11Forwarding yes   should be commentout

[root@test ~]# grep -i x11* /etc/ssh/sshd_config
#X11Forwarding no
X11Forwarding yes
#X11DisplayOffset 10
#X11UseLocalhost yes
#       X11Forwarding no

>> make sure you added the right key

>> xauth list         <,,,you will get the output>>>>>>

#xauth add <add here which got xauth list output>

then it will be work. check with xclock commnd

#xclock

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some more useful commands

echo $DISPLAY

export DISPLAY=localhost:10.0

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