Configure your server after the package dtc-xen is installed
dtc-xen_finish_install
This shell script is a part of the dtc-xen package that is to be used by the dtc panel to manage a Xen VPS server.
This script has no parameter and will first add an entry in your /etc/sudoers like this:
%xenusers ALL= NOPASSWD: /usr/sbin/xm console xen*
Then it will set the following in your sshd_config:
AllowTcpForwarding no
This documentation describes dtc-xen_finish_install
See http://www.gplhost.com/software-dtc-xen.html for updates.