To make sure that '''tun''' module will be automatically loaded on every reboot you can also add it or into /etc/modules.conf (on RHEL: echo 'modprobe tun' >> see /etc/sysconfig/modules/tun.modulesdirectory) or into /etc/sysconfig/vz-scripts/''VEIDCTID''.mount. (echo 'modprobe tun' >> /etc/sysconfig/vz-scripts/''VEIDCTID''.mount)