macOS client, _cups mDNS subtype and shared IPP Everywhere queues

[dkosovic]

For a CUPS server, assume we have the following in cupsd.conf :

BrowseDNSSDSubTypes _cups,_print,_universal

(the above 3 mDNS subtypes are the default in later versions of CUPS even if not explicitly set in `cupsd.conf``)

The _cups mDNS subtype is used by a CUPS server to advertise that a print queue is shared. On macOS clients when adding the corresponding print queue, the queue is listed as Bonjour Shared.

Unfortunately, when _cups is used, macOS clients seem to want to use a printer driver that has been previously installed (or a driver that can be downloaded from Apple Updates).

If the _cups mDNS subtype is not used, then /System/Library/Printers/Libraries/ipp2ppd is automatically used as the PPD generator like it does with AirPrint printers. I'm not using the _cups mDNS subtype at the moment, but had to do minor modifications to the CUPS source code when it detects a macOS client to prevents page manipulation features like number-up from being applied twice (which doesn't happen if _cups is used`).

Is there a way to get macOS clients to recognise Bonjour advertised shared print queues (i.e. with _cups mDNS subtype) as either AirPrint or IPP Everywhere?

[michaelrsweet]

Unfortunately no. As soon as they see the _cups sub-type they will treat it as a CUPS shared printer.