I looked at the lprng changelog and tracked down a previous closed bug report and figured out that "lpd_listen_port=515" has to be in /etc/lprng/lpd.conf in order for remote printing to work. I noticed this comment before someplace in the documentation, but then forgot about it. Suggestion: Put this command commented out in the default lpd.conf file, so it is easy for people to turn on remote printing if necessary. Dave Raymond