If you can not seem to get any of the CUPS clients to print to
your CUPS server, you may have forgot to install cups-lpd.

      yum install cups-lpd

You may have also forgot to configure t:


-----> EL6:

Edit /etc/xinetd.d/cups-lpd and change "disabled" to "no":

# default: off
# description: Allow applications using the legacy lpd protocol to 
communicate with CUPS
service printer
{
	disable = no
	socket_type = stream
	protocol = tcp
	wait = no
	user = lp
	server = /usr/lib/cups/daemon/cups-lpd
}



Get xinetd's PID:
          ps ax | grep -i xinetd

if not running, start xinetd:
          /etc/rc.d/init.d/xinetd start

if running, do a kill with a SIGHUP on xinetd to reread this file:

          kill -SIGHUP pid_xinetd



-----> EL7:

Xinetd: if you installed it just for cups-lpr, then remove it:
         # rpm -e xinetd

    Otherwise, if you need xinetd, remove
        /etc/xinetd.d/cups-lpd

    and restart xinetd with
        # service start xinetd


# systemctl enable cups-lpd.socket
# systemctl start cups-lpd.socket