First make sure that your /dev/lp* port is correctly configured. Its IRQ (if any) and port address need to match the settings on the printer card. You should be able to dump a file directly to the printer:

   $ cat the_file >/dev/lp1

If lpr gives you a message like myname@host: host not found" it may mean that the TCP/IP loopback interface, lo, isn't working properly. Loopback support is compiled into most distribution kernels. Check that the interface is configured with the ifconfig command. By Internet convention, the network number is 127.0.0.0, and the local host address is 127.0.0.1. If everything is configured correctly, you should be able to telnet to your own machine and get a login prompt.

Make sure that /etc/hosts.lpd contains the machine's host name.

If your machine has a network-aware lpd, like the one that comes with LPRng, make sure that /etc/lpd.perms is configured correctly. Also look at the Printing HOWTO. "Where can I get the HOWTO's and other documentation? ".