One of the features of lpd is that it supports printing over the network to printers physically connected to a different machine.
To allow remote machines to print to your printer, you must list the
machines in /etc/hosts.equiv or /etc/hosts.lpd.
(Note that hosts.equiv has a host of other effects; be sure you
know what you are doing if you list any machine there). You can allow
only certain users on the other machines to print to your printer by
usign the rs attribute; read the lpd
man page for
information on this.
To print to another machine, you make an /etc/printcap entry like this:
# REMOTE djet500
lp|dj|deskjet:\
:sd=/var/spool/lpd/dj:\
:rm=machine.out.there.com:\
:rp=printername:\
:lp=/dev/null:\
:sh:
Note that there is still a spool directory on the local machine
managed by lpd
. If the remote machine is busy or offline, print
jobs from the local machine wait in the spool area until they can be
sent.