Duplicate printer showing in apps but not in CUPS, how to remove??

[ajm83]

Hi, I have a question about printers, specifically I want to know why a printer is listed twice in the print screen on various programs:

Screenshot from 2019-03-29 21-46-54.pngScreenshot from 2019-03-29 21-47-22.png

Yet in the Printers control panel, it is only listed once:
Screenshot from 2019-03-29 21-49-51.png

And only once on the CUPS web UI:

Screenshot from 2019-03-29 21-50-09.jpg

And only once in lpstat:

lpstat -s
system default destination: HP-LaserJet-CP-1025nw
device for HP-LaserJet-CP-1025nw: ipp://NPI96054C.local:631/printers/HP_LaserJet_CP1025nw

The problem is that for whatever reason people clicking the duplicate one, and it does not work.

Does anybody know where it comes from and how to remove it? Thanks!!

[ajm83]

Made some progress! I discovered that lpstat -ev shows the duplicate:

lpstat -ev
HP-LaserJet-CP-1025nw
HP_LaserJet_CP_1025nw
device for HP-LaserJet-CP-1025nw: ipp://NPI96054C.local:631/printers/HP_LaserJet_CP1025nw

This lead me to this answer to someone with the same problem (and a different brand of printer, mine's HP)
https://askubuntu.com/questions/6768...inter-in-gnome

Anyway it looks like some kind of non-functional autodiscovery over the network. In my case, disabling bonjour on the printer's web config removes it from the print dialog.

For anyone who finds this via google, the setting in question is found here:

[brian_p]

Please enable Bonjour on the printer and give the outputs of

avahi-browse -rt _ipp._tcp

lpstat -l -e

With Bonjour disabled there is probably only one entry shown in the LibreOffice print dialog. Can you print to it?

[brian_p]

With Bonjour disabled there is probably only one entry shown in the LibreOffice print dialog. Can you print to it?

I've changed my mind over this. You have

• device for HP-LaserJet-CP-1025nw: ipp://NPI96054C.local:631/printers/HP_LaserJet_CP1025nw

This is an auto-setup configuration by cups-browsed (why CP-1025nw and not CP1025nw?). cups-browsed gets it from Bonjour, so it will not be found if Bonjour on the printer is turned off. Nothing should be shown in the Printers control panel and the CUPS web interface or in any print dialog.

[brian_p]

Irrespective of whether the original query has been completely treated, it would still be very useful for other purposes (troubleshooting in future printing problems, for example) to have the output of

avahi-browse -rt _ipp._tcp

[ajm83]

Sorry Brian, I didn't get notified about your replies, I will re-enable Bonjour on the printer and grab the output tonight from the commands you listed.

With Bonjour disabled there is probably only one entry shown in the LibreOffice print dialog. Can you print to it?

With Bonjour disabled I have one working printer that I think was autodiscovered and shows in the Printers control panel.

With Bonjour enabled, I have that same printer, still working, plus one listed as REJECTING JOBS. Same as in the post I linked from AskUbuntu.com above.

[brian_p]

Thank you for getting back to us, ajm83.

With Bonjour disabled I have one working printer that I think was autodiscovered and shows in the Printers control panel.

I'll have to think about this; I am unsure whether it is the result of autodiscovery. Please add the output of

lpstat -t

to the other information you supply.

With Bonjour enabled, I have that same printer, still working, plus one listed as REJECTING JOBS. Same as in the post I linked from AskUbuntu.com above.

This is shown in the GTK print dialog (used by Firefox and evince). The REJECTING JOBS is the result of a bug in the way the dialog gets an entry for a network printer.

https://gitlab.gnome.org/GNOME/gtk/issues/1509

Turning off Bonjour on the printer is one way of not having a non-working entry, as you have demonstrated. There are drawbacks to that though when it comes to LibreOffice, whose dialog behaves in a different way from FireFox's.

[ajm83]

As requested:

avahi-browse -rt _ipp._tcp

root@howard:~# avahi-browse -rt _ipp._tcp
+ wlp1s0 IPv4 HP LaserJet CP 1025nw                         Internet Printer     local
= wlp1s0 IPv4 HP LaserJet CP 1025nw                         Internet Printer     local
   hostname = [NPI96054C.local]
   address = [192.168.1.90]
   port = [631]
   txt = ["Staple=F" "Sort=F" "Scan=F" "Punch=0" "PaperCustom=F" "Duplex=F" "Copies=F" "Color=T" "Collate=F" "Bind=F" "Binary=T" "Transparent=T" "UUID=17a8cd2e-c532-5844-90ed-11f2f91cb0f5" "note=Spare Bedroom" "adminurl=http://192.168.1.90" "mac=34:64:A9:96:05:4C" "priority=40" "usb_CMD=ZJ/URF" "usb_MDL=HP LaserJet CP 1025nw" "usb_MFG=Hewlett-Packard" "product=(Hewlett-Packard HP LaserJet CP 1025nw)" "ty=HP LaserJet CP 1025nw" "URF=CP1,IS1,OB10,PQ3-4-5,RS600,W8,SRGB24,MT1-2-3-4-5-6-8-10-11-12" "rp=printers/HP_LaserJet_CP1025nw" "pdl=image/urf,application/PCLm" "qtotal=1" "txtvers=1"]

lpstat -l -e

root@howard:~# lpstat -l -e
HP-LaserJet-CP-1025nw permanent ipp://localhost/printers/HP-LaserJet-CP-1025nw ipp://NPI96054C.local:631/printers/HP_LaserJet_CP1025nw
HP_LaserJet_CP_1025nw network none ipp://HP%20LaserJet%20CP%201025nw._ipp._tcp.local/

lpstat -t

root@howard:~# lpstat -t
scheduler is running
system default destination: HP-LaserJet-CP-1025nw
device for HP-LaserJet-CP-1025nw: ipp://NPI96054C.local:631/printers/HP_LaserJet_CP1025nw
HP-LaserJet-CP-1025nw accepting requests since Fri 29 Mar 2019 21:36:43 GMT
printer HP-LaserJet-CP-1025nw is idle.  enabled since Fri 29 Mar 2019 21:36:43 GMT

[brian_p]

From the avahi-browse output:

• rp=printers/HP_LaserJet_CP1025nw

rp= is the Resource Path for the printer. Firefox uses this to put an entry (non-working due to a bug) in its dialog. You can replace this entry by one with the same name with

lpadmin -p HP_LaserJet_CP1025nw -v ipp://NPI96054C.local:631/printers/HP_LaserJet_CP1025nw -E -m everywhere

This should give a working entry and, with Bonjour operative, the printer will still be visible on the network to other devices and their applications.

[ajm83]

From the avahi-browse output:

• rp=printers/HP_LaserJet_CP1025nw

rp= is the Resource Path for the printer. Firefox uses this to put an entry (non-working due to a bug) in its dialog. You can replace this entry by one with the same name with

lpadmin -p HP_LaserJet_CP1025nw -v ipp://NPI96054C.local:631/printers/HP_LaserJet_CP1025nw -E -m everywhere

This should give a working entry and, with Bonjour operative, the printer will still be visible on the network to other devices and their applications.

Thanks for this.

There are three bugs here IMO.

1. Non-operative printer, as discussed.
2. Non-operative printer not appearing in the Printers control panel therefore unable to be disabled or inspected by a regular computer user who is unfamiliar with the command line.
3. The same printer appearing twice in the first place. The system should recognise that this is the same printer and show only the best method of connecting to it.

What do you think?