Issues with CUPS and system printer support and LAN

[geezer]

Found some rather weird performance with CUPS and the system printer support.

System: Kubuntu 13.04 on both desktop and laptop. Both connected in LAN through router.

3 printers:
HP Color LaserJet CM1312nfi MFP
HP 5740 DeskJet
HP 1220se LaserJet

All 3 printers connected to desktop computer via USB.

All three printers setup and recognized by CUPS and the System Settings->Printers s/w on the Desktop computer. Both Cups and the System Settings s/w woutput test pages on all 3 printers.

Both CUPS and System Settings s/w set to share all printers.

Now on the laptop, when I open Firefox and open the CUPS page, I get 8 printers (the Fax function on the Color LaserJet CM1312nfi MFP counts as a separate printer). On the Desktop, CUPS shows only 4 printers.

On the desktop CUPS shows: see first attachment

On the laptopn CUPS shows: see second attachment

As you can see, the laptop shows 8 printers under CUPS. On the laptop, if I click on any of the printers with "Remote Printer" under "Make and Model", then Firefox display an error message that address wasn't understood: see third attachment.

Notice the address displayed in Firefox, namely: ipps://Home-Net.local:631/printers/DeskJet_5700

If I click on one of the printers in CUPS on the laptop that isn't a "Remort Printer" under "Make and Model", then I get a proper printer display: see attachment 4

Notice the address displayed by Firefox for this printer, namely: localhost:631/printers/HP_Color_LaserJet_CM1312nfi_MFP

very different.

It gets wierder. I can print a document and in the dialog to choose a printer only 4 printers are shown and the document will print on any of the 3 printers (I don't print to the fax).

Now on the desktop, if I open the System Settings->Printers and click on "System Preferences" and then "Share Printers connected to this System" so that the item is not selected. Then look at the CUPS page on the laptopn, 4 of the printers have disappeared: see attachment 5:

If I click on any of the 4 printers now shown, I get a valid page displayed in Firefox.

However, If I try to print a test page on any printer under CUPS on the laptop, the system is now unable to find the printer: see attachment 6 (hmm I seem to have reached a limit and cannot attach any more images)

If I try to print a page in an app, I don't get any error message, but the page to print doesn't get to the printer.

If I then share printers under System Settings->Printers on the desktop, the printer is then found by the laptop and the test page is printed and the app page also.

So on the desktop, if I share printers with both CUPS and System Settings->Printers I get doubling of the printers on the laptop, of which 1/2 are not accessible through CUPS. If I unshare the printers on the desktop through System Settings->Printers, then the Laptop sees only the 4 printers, but is unable to find them when something is actually printed. Sharing the printers again under System Settings->Printers makes the printer available on the laptop and the doc get printed.

This does not work if I unshare printers under CUPS on the Desktop.

Something weird is happening between CUPS and System Settings->Printers.

[oshunluvr]

What's are the admin settings for sharing printers? It should not have "share printers attached to this system" selected on the laptop.

I've found it double up in the past if I installed the printer manually, and then later the printer was "discovered" automatically.

In theory, you should be able to delete all the printers from the laptop, make sure "Share printer..." is not ticked on the laptop, then search for netwrok printers and they will show up.

[Snowhog]

oshunluvr@

That isn't how I have CUPS Admin set on my two laptops. My 'network' is similar to the OP but 'smaller'. I have two laptops connected to my Linksys router and a single laser printer connected via USB to my primary laptop. I share that printer with my second laptop. CUPS Administration > Server Settings has Share printers connected to this system checked on my primary laptop. On the second laptop, CUPS Administration > Server Settings > Share printers connected to this system is unchecked.

[geezer]

What's are the admin settings for sharing printers? It should not have "share printers attached to this system" selected on the laptop.

I've found it double up in the past if I installed the printer manually, and then later the printer was "discovered" automatically.

In theory, you should be able to delete all the printers from the laptop, make sure "Share printer..." is not ticked on the laptop, then search for netwrok printers and they will show up.

oshunluvr@

That isn't how I have CUPS Admin set on my two laptops. My 'network' is similar to the OP but 'smaller'. I have two laptops connected to my Linksys router and a single laser printer connected via USB to my primary laptop. I share that printer with my second laptop. CUPS Administration > Server Settings has Share printers connected to this system checked on my primary laptop. On the second laptop, CUPS Administration > Server Settings > Share printers connected to this system is unchecked.

The laptop does not have share printers selected.

I have deleted all printers from the laptop 2 or 3 times and then when I reboot, the same thing always happens -- the printers are doubled up. I have found that since CUPS on the laptop cannot "see" the "Remote Printer" and hence cannot manage those printers, I have to use the laptop System Settings->Printers to delete the printers that CUPS labels as "Remote Printer"

It would seem to me that CUPS on the laptop is "discovering" one set of printers from CUPS on the desktop and maybe the laptop System Settings discovers another set of the same printers from the desktop System Settings. This gives me a doubled up set of printers.

This isn't a disabling problem, just irritating.

[oshunluvr]

oshunluvr@

That isn't how I have CUPS Admin set on my two laptops. My 'network' is similar to the OP but 'smaller'. I have two laptops connected to my Linksys router and a single laser printer connected via USB to my primary laptop. I share that printer with my second laptop. CUPS Administration > Server Settings has Share printers connected to this system checked on my primary laptop. On the second laptop, CUPS Administration > Server Settings > Share printers connected to this system is unchecked.

That's what I was trying to say - I guess I didn't say it well.

[geezer]

I just realized that there are 3 players in the issue, not just System Setting->Printers and CUPS.

The playeers are:

1. Sytem Settings->Printers
2. CUPS
3. webmin

Which one is producing the doubled printers is difficult to say. If I look at Hardware->Printer Administration on the laptop, I have the following (attachment 1)

which shows that weird address to print to. I wonder where that is coming from??