I have a thin client with 112mb RAM which boots ubuntu server 12.04.1 from a usb drive with openbox and it is to be used by students to communicate with cisco equipment. And because of this the students need to be able to reconfigure the network interface and then restart it without a reboot using the only user - cisco. This is what I have so far: adduser cisco usermod -a -G dialout cisco chown root:cisco /etc/network/interfaces chmod 664 /etc/network/interfaces chmod u+s /sbin/shutdown chmod u+s /sbin/reboot chmod u+s /sbin/poweroff chmod u+s /run/network/if* chmod u+s /sbin/ifdown chmod u+s /sbin/ifup And when I run /etc/init.d/networking restart as cisco I get: *Reconfiguring network interfaces... rm: cannot remove `eth0.dhclient': Permission denied Failed to send flush request: Operation not permitted RTNETLINK answers: Operation not permitted Any ideas on how to get this working? Thanks!