Much to my surprise, I encountered this error message when connecting to a RHEL6.3 server in order to remote display a RAID controller management app.
jhoblitt@foo ~ $ ssh -X foo2 Warning: untrusted X11 forwarding setup failed: xauth key data not generated Warning: No xauth data; using fake authentication data for X11 forwarding. X11 forwarding request failed on channel 0
It seems that an update to OpenSSH changed the semantics of X11 forwarding. A bit of googling turned up the answer in this thread:
The fix is to add this line to your
In previous version just
X11Forwarding yes was needed but it seems that both directives are now required.
I’m not sure when this change was introduced but it’s definitely present in this version of sshd:
[jhoblitt@pfoo2 ~]$ ssh -V OpenSSH_5.3p1, OpenSSL 1.0.0-fips 29 Mar 2010 [jhoblitt@foo2 ~]$ rpm -qa | grep openssh openssh-clients-5.3p1-81.el6.x86_64 openssh-5.3p1-81.el6.x86_64 openssh-server-5.3p1-81.el6.x86_64