Ever get the following issue when trying to X-forward?

ssh -X root@192.168.124.29
root@192.168.124.29's password:
X11 forwarding request failed on channel 0

Huh?

ssh -vX root@192.168.124.29
root@192.168.124.29's password:
<snip>
debug1: Remote: No xauth program; cannot forward with spoofing.
X11 forwarding request failed on channel 0

Duh!

# yum install xauth