[Installation] CUPS authentication question from new install

[clh333]

I am sorting through configuration issues with a fresh install of kubuntu 20 lts from a live CD. The machine is a dual-boot ASUS / AMD. It previously ran Fedora 24 through 33.

The live install identified and installed a printer, a Brother MFC-J497DW multifunction. There are two such printers here: one is attached to this machine via USB and another is on the wi-fi network. In addition there is a Canon PIXMA Pro 9000 Mark II, also attached by USB to this machine, and a Dell 1720 laser that is networked by cable to the wi-fi router. They all work in Windows 10; they all worked in Fedora 32, which was accidentally destroyed, as described in another post.

The Brother printer does not respond to commands - print a test page, for example. Brother has published Linux drivers for their machine, bless their hearts, and although the drivers are not installed here I have installed them before on other Fedora systems. But my question has to do with another issue:

Before installing the Brother drivers I wanted to remove the machine that the live install created. I could not do so through the desktop interface. I'd delete it and it would pop back. I researched the Internet and found a suggestion to delete it through the CUPS interface at http://127.0.0.1:631/printers. I got there and found the printer ("driverless") and attempted to delete it. I was asked for authentication and gave my UN / PW, but was asked for authentication again. I tried "root / ROOTPW" and that was refused again. An error message stated that if I was using kerberos authentication to make sure I had a kerberos ticket.

Okay, now I'm lost. Is this kerberos authentication? how do I create a ticket? What is CUPS looking for?

Thanks for your suggestions.
-CH-

[jlittle]

There's a long standing issue here. I eventually managed to work out how to delete the printer, but it would come back within a few minutes. Presumably there's a service that watches the local network and adds printers it finds, despite an identical printer already existing. I ran out of willingness to keep fighting it, and left it but set to disabled. This was when 18.04 came out; I'd previously done the driver install about a year before. I've seen other reports of this nuisance.

Then, the story took another turn about a year later when a borked file system made a reinstall seem a good idea. I forgot about the printer driver stuff in the drama of resurrecting the OS, and a couple of months later realised that I was happily printing without having given it any thought. The automatically installed device works fine without installing drivers. I had some trouble with the scanner at some point, and xsane and "simple scan" were crashing. But skanlite stepped into the breach, I think. There was a weird font issue.

[clh333]

There's a long standing issue here.

I had some trouble with the scanner at some point, and xsane and "simple scan" were crashing.

Thanks for your response. I would hate to lose XSANE, as I have an Epson scanner with a transparency unit that is quite useful. XSANE is the only application, to my knowledge, that still supports it.

The Epson driver worked well with Windows XP but Epson never upgraded it and Windows couldn't care less. I'll keep trying 'til I find something that prints.

Thanks again,

-CH-

[clh333]

Happy to report that I have inadvertently resolved the printer issue by means of Gutenprint. The Synaptic package manager installed the Gutenprint driver and related files, by means of which I was able to install a driver for the Canon 9000 Mark II ink jet printer and the Dell 1720dn laser printer. Each will now print text in greyscale, which is the only option for the Dell anyway. I'm not sure about color on the Canon but at least it responds. I also downloaded and installed the Brother Linux drivers for the MFC-J497DW multifunction printer, and the system recognizes two of them; one is connected to the kubuntu machine via USB cable, the other is on the local network via wi-fi. I have printed to each.

Best of all I am able to use XSANE with the Epson scanner. It also recognizes the Brother scanners but I can't connect to them for operation yet. Nor have I solved color printing to the Brother printers.

Thanks for your help,

-CH-