Mystery printer in firefox under Ubuntu 14.04.5

[Robert Heller]

At Thu, 16 Mar 2017 18:21:26 +0000 "Ubuntu user technical support,  not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:

> 
> On Thu 16 Mar 2017 at 10:48:35 -0400, Robert Heller wrote:
> 
> > At Thu, 16 Mar 2017 11:40:05 +0000 "Ubuntu user technical support,  not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:
> > 
> > > 
> > > On Wed 15 Mar 2017 at 17:36:18 -0400, Robert Heller wrote:
> > > 
> > > > For some unknown reason a "mystery" printer is showing up in FF's selection of
> > > > printers. This printer does NOT show up in 'lpstat -t'. It is not in
> > > > /etc/cups/printers.conf. And I know for sure that I uninstalled the (stupid)
> > > > deamon that finds new random printers (don't need or want that sort of "user
> > > > friendliness"). Is this a Ubuntu issue or a Firefox issue or a Unity/Gnome
> > > > issue? I have not seen this on my CentOS machines, ever. It only seems to
> > > > happen on the diskless Ubuntu machines I set up using DRBL.
> > > 
> > > Please post
> > > 
> > > 1. The entry for this printer in Firefox's print dialog.
> > 
> > Don't have the exact thing right now -- the machine in question is not powered
> > up right now and I am not presently at the library. It is something like
> > "NPI76<more digits>"
>  
> My HP LaserJet has a default hostname which begins "NPI".
>  
> > > 2. The name of the "(stupid) deamon".
> > 
> > cups-browsed
> > 
> > This daemon is (I guess) meant to be helpful (?) on a laptop that 'roams'
> > about and it seems to find new printers and/or remove printers that are no
> > longer available. We don't want / need this on *hard (network) wired*
> > workstations with a pair of *hard (network) wired* printers.  We don't want 
> > printers coming and going automagically.
> 
> cups-browsed is also useful for machines which do not roam but, as you
> say, you have no need of it. Without it the cups daemon will only see
> the local print queues you have configured on a machine. They are in
> printers.conf and shown by 'lpstat -t'.

Yes, that is the intent.

> 
> > > 3. The outputs of
> > > 
> > > 	/usr/sbin/lpinfo -v
> > > 	lpstat -t
> > > 	systemctl status avahi-daemon.service
> > 
> > 
> > On the Ubuntu VM server (serves the /tftpboot of the kernel, the root and /usr 
> > file systems to the PXE booting diskless workstations):
> 
> [Snip]
>  
> > network dnssd://hp%20LaserJet%204200%20(0001E67659FE)._pdl-datastream._tcp.local/
> 
> This is a URI for the LaserJet 4200. The machine it is connected to is
> running CUPS and doing Bonjour broadcasting. You have not used this URI
> to set up a print queue for the printer.

Right, I want the printing to go through the CentOS 6 server and not have the 
various workstations queuing to the printer itself.

> 
> > ub140464.wendellfreelibrary.org% lpstat -t
> > scheduler is running
> > system default destination: BrotherColorLaser
> > device for BlackandWhiteLaserjet: ipp://192.168.1.251:631/printers/BlackandWhiteLaserjet
> 
> This is the URI you have used to set up a print queue for the Laserjet
> 4200.

Yes.

> 
> > device for BrotherColorLaser: socket://192.168.1.252
> 
> Looks like you are sending print jobs directly to the MFC-9970CDW.

Yes.  Not what I wanted, but the MFC-9970CDW is a picky beast.

> 
> > BlackandWhiteLaserjet accepting requests since Sat 27 Sep 2014 05:47:52 PM EDT
> > BrotherColorLaser accepting requests since Fri 05 Dec 2014 04:03:05 PM EST
> > printer BlackandWhiteLaserjet is idle.  enabled since Sat 27 Sep 2014 05:47:52 PM EDT
> > printer BrotherColorLaser is idle.  enabled since Fri 05 Dec 2014 04:03:05 PM EST
> > 
> > There is no systemctl.  The machines are not running systemd, they are Ubuntu 
> > 14.04.5 and using upstart.
> 
> I was only after whether you had avahi-daemon running on the network,
> The dnssd URI indicates you have.
> 
> > I will get the exact info from one of the workstations later today.
> > 
> > > 4. The makes/models of printers on the network.
> > 
> > HP LaserJet 4200
> > Brother MFC-9970CDW
> > 
> > > We assume you have a wireless-enabled network.
> > 
> > There is wireless, but all of the workstations are hard wired and none have 
> > wireless.  Both printers are hard wired.  One printer does not have wireless 
> > (the *old* HP B&W LaserJet) and the other has the wireless turned off.
> > 
> > The Ubuntu "server" is running as a VM on a CentOS 6 machine.  The CentOS 6 is 
> > the main file server (/home) and is also the DNS, DHCP, and LDAP server.  It 
> > is also the network print server (or at least tries to be).  Both the Ubuntu 
> > "server" and the CentOS 6 machine provide tftp and nfs services.
> 
> cups-browsed browses Bonjour broadcasts of remote print queues and
> printers and sets up local queues for them. cupsd sees these queues and
> displays them in an app's print dialog. Stopping or uninstalling
> cups-browsed means remote print queues or printers will not be visible
> in dialogs **via the agency of cupsd**.
> 
> However, the GTK printing subsystem is capable of browsing Bonjour
> broadcasts all by itself, without the need for cupsd. This is what you
> are observing when you see the extra print queue. Examining the output
> of
> 
>  avahi-browse -art | less
> 
> should show the culprit. Does it?

Yes.  How do I stop it?

> 

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