[cups.general] how to get printers on mac os 10.8 from a linuxcups in a different subnet

Michael Sweet msweet at apple.com
Wed Nov 7 13:01:40 PST 2012


On 2012-11-07, at 3:18 PM, franz.pfoertsch.brose <franz.pfoertsch at brose.com> wrote:
> ...
> I could not understand, what the reason was to disable cups browsing for everybody. It is very helpfull in structured networks.
> Why did you remove cups protocol complete?

Because it didn't work for a lot of people (more than it worked for).

Because supporting it in cupsd involved a large amount of code with lots of special-casing.

Because the CUPS browsing protocol requires the client and server to stay awake all of the time to send and receive packets, which are broadcast (all machines need to process them whether they want to or not, drop Wi-Fi to lowest possible speed) and/or polled/relayed (to get across subnets) - that uses a lot of energy, bandwidth, and CPU, and requires a lot of configuration on a big network to deal with subnets.

> You also could mark cups browsing as deprecated and disable it by default.

It *was* deprecated in CUPS 1.5 and has been disabled by default since at least CUPS 1.2.

> In my opinion you break cups for Linux and structued networks.

You don't need to upgrade if you rely on legacy support.  And structured networks are built on DNS, which is the basis of Bonjour!


If you are supporting Active Directory via Linux, then you should be using some version of Samba on your servers to support the Windows clients.  Any Linux clients can either use BrowsePoll to the new servers (if the clients are still running CUPS 1.5 or earlier) or use statically-configured printers (lpadmin -p printer -E -v ipp://servername/printers/printername) to get equivalent functionality (all versions of CUPS).  If the clients are still running older versions of CUPS, BrowsePoll and BrowseRelay will still work when pointed at the new servers.

Michael Sweet, Senior Printing System Engineer, PWG Chair

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