[Wylug-help] Network Printing (Cups and HP/HPLIP) On Ubuntu

[Dave Fisher]

Hi,

Can anyone give me an idea about how network printing using HP Linux
Imaging and Printing (HPLIP) is supposed to work on Debian/Ubuntu?

The hp-toolbox app tells me I must use the CUPS web interface to
initially setup and intall drivers.

Ubuntu disables configuration through the CUPS web interface and
insists that I use the desktop GUI.

   System > Administration > Printing

This GUI (gnome-cups-manager ?) didn't automatically detect the attached
printer (HP PSC2110 on /dev/usb/lp0) initially. 

After a reboot and some directionless fiddling with various hp
under-documented command line utilities (e.g. hp-probe, hp-levels,
hp-makeuri) it did detect the device, but I'm not sure what did the
trick.

gnome-cups-manager seemed to come right after I ran:

  hp-makeuri /dev/usb/lp0

but that may have been entirely coincidental.

After gnome-cups-manager detected the local printer and I selected it, I could
print from all local apps and from the local command line.

Unfortunately, this isn't much use to me, since I generally work on
other hosts and need to print across my LAN. 

I can't see an option in gnome-cups-manager which would allow me to do that.

Having configured /etc/cups/cupsd.conf to listen on port 631 on the server's
external address, nmap (from the client host) confirms that the port is open:

  PORT     STATE SERVICE
  631/tcp  open  ipp

But hp-probe -bnet from both client and server shows this:

 [WARNING]: No devices found. If this isn't the result you are expecting,
 [WARNING]: check your network connections and make sure your internet
 [WARNING]: firewall software is disabled.

As far as I am aware, the print server has no firewall running on it and cups
is not running under inetd.  On the other hand, previous experience reminds me
that cups has quite a bit of its own access and authentication.

I presume that there is some simple (and safe) way of allowing print jobs to be
submitted from IP addresses on the LAN, but I've used up all the time I set
aside to get this thing sorted.

Time-saving tips would, therefore, be much appreciated.


Dave