Re: Recommended way to manually add an undiscovered IPP printer in CUPS 3.x

On 8/2/26 00:46, Alexander Pevzner wrote:
> Till,
> 
> I think this is a bad idea for users to disable DNS-SD. It breaks not only 
> printing, but driverless scanning as well.
> 

There can be corporate settings with DNS-SD turned off.

> Providing user a method to somehow workaround disabled DNS-SD just creates a 
> wrong illusion that we somehow support this mode of operation.
> 

The printer setup tool needs to work for everybody, also those in said corporate 
environment. And if DNS-SD is on, the printers in the local network appear 
readily available in the main view. So the user sees their printer already and 
so does not click on "Add Printer".

Also, the printer setup tool know whether DNS-SD is on or off, and with DNS-SD 
on, the options not making sense in "Add Printer" then could not be shown, to 
simplify "Add Printer" for the users who have DNS-SD on.

> That said, adding driverless printer manually still a useful option in case the 
> printer is connected to the non-local LAN segment.
> 

Yes, this is important and "Add Printer" should always display this option.

> At this case it doesn't make a lot of sense to probe for the ipp-usb managed 
> printers (which, BTW, may have assigned ports not only 60000 and 60001, but any 
> subsequent port as well),
> 

Probing for IPP-over-USB printers I only intended for the case of DNS-SD off 
(and there check more ports, perhaps up to 60010).

> Regarding normal hardware printers, are there really printers out of existence, 
> that can respond IPP requests on alternative ports but doesn't respond on a 
> standard port 631? If not, there is not a lot of sense to probe ports 8000, 8001 
> etc.
> 

Port 8000+ is for Printer Applications, not for driverless hardware network 
printers.

    Till