SNMP printer discovery documentation?

[John A. Murdie]

Kurt Pfeifle wrote at 16:35 Wed:
> Heh...
>
> I had not intended to send you a print job :-)  Nor do even more
> evil things to it  :-)

Nothing personal, Kurt; I could only imagine that you wanted to access it from where you are, but it's just that my systems are behind the campus firewall over which I have no control. I am not allowed to ask for a hole to be made in it.

> > What would you have looked for?
>
> I'd just have checked if they are in the same subnet, if netmasks
> match etc. (However, if commandline snmp works that should be a
> given).

Yes, all the clients and the host in my current evaluation of CUPS are on the same subnet (=> same netmask).

> snmp broadcasts will not work across routers or gateways into the
> neighboring subnets... (However, when I made my snmp.conf file
> really large by enumerating each single IP address of another
> subnet [256 addresses], auto-discovery indeed did come back with
> 42 network printers over there, albeit very slow [2 minutes, 10
> seconds] -- I'll file a bug report about it, once I collected
> some more debugging info...)
>
> >> What is the output of "ifconfig" on your system?
> >
> > It's as expected. What would you have looked for?
>
> See above  :-)
>
> Cheers,
> Kurt

What baffled me was that the printer I am sure that I have never added to my CUPS 1.2.2 printers.conf (which was copied from what I'd set up for an experimental installation of CUPS 1.1.23 - definitely not there in the original) didn't come up listed after the style of the first example from your posting of 10:46 on Wednesday, but in the manner of the second example.

>> *If* the snmp backend did discover (uninstalled) printers, it
>> will display them in a list on the admin page, like this
>> screenshot shows:
>>
>>     http://www.kdedevelopers.org/node/2126
>>
>> If your screenshot does look more like this:
>>
>>     http://www.kdedevelopers.org/node/2127
>>
>> then the snmp backend did not discover an IP address that is
>> a printer that is not yet installed on the system.

I've checked again now, and the printer is definitely not in the printers.conf file of my CUPS 1.2.2 installation when I start, yet when I try to 'Add New Printer' it, I see the second form above. Yet, when I run the snmp backend stand-alone as described by article #387, the new printer is found and correctly identified. Finally, the printer is added and I see an entry appear for it in printers.conf. I've still not seen the first dialogue.

I've tried a final experiment. I've stopped the CUPS scheduler and edited printers.conf to remove another printer which snmp finds ok. Then I try 'Administration' -> 'Add New Printer'. The same thing happens as before; I never see a screen like your first screenshot.

All this is rather painful to do because of the long delays (sometimes 5, sometimes 40 minute) involved in moving from one screen to another in the CUPS management web interface.