Forwarding X over ssh is normally fairly straightforward when you have the correct packages installed. I have another post about the errors that appear when you’re missing the xorg-x11-xauth (CentOS, Fedora, RHEL) or xauth (Debian, Ubuntu) packages. Today’s error was a bit different. Each time I accessed a particular Debian server via ssh with X forwarding requested, I saw this: $ ssh -YC X11 forwarding request failed on channel 0 The xauth package was installed and I found a .