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

[Johannes Meixner]

Hello,

On Nov 7 16:01 Michael Sweet wrote:
> On 2012-11-07, at 3:18 PM, franz.pfoertsch.brose <franz.pfoertsch at brose.com> wrote:
....
>> 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.

At least in the CUPS 1.5 documentation for the cupsd at
http://www.cups.org/documentation.php/doc-1.5/ref-cupsd-conf.html
none of the "Browse..." configuration directives is marked as
deprecated (like the AuthClass and AuthGroupName configuration
directives are).

According to this documentation the defaults for CUPS 1.5 are
in particular:
------------------------------------------------------------------
BrowseAddress
....
There is no default browse address.
------------------------------------------------------------------
and
------------------------------------------------------------------
BrowseAllow
....
The default is to accept browse packets from all hosts.
------------------------------------------------------------------
and
------------------------------------------------------------------
Browsing
....
The default setting is Yes.
------------------------------------------------------------------

I get the same documentation on http://localhost:631
on my Linux worksatation which runs CUPS 1.5.4.


That defaults exist "since ever" and match what is described
as "Intrinsic design of CUPS for printing in the network" at
http://en.opensuse.org/SDB:CUPS_in_a_Nutshell


For CUPS 1.1 any cupsd did broadcast its local printers by
default (i.e. the BrowseAddress was not empty by default)
and that was bad in networks because when John Doe connected
his laptop to a network or when he set up local printers on
his workstation his local cupsd would broadcast John Doe's
printers on the network which is usually neither wnted by
John Doe nor by the other users (and admins) of the network.

Therefore since a CUPS 1.1.N version or at least since CUPS 1.2
BrowseAddress is empty by default but Browsing is and was enabled
all the time by default up to CUPS 1.5.


>> 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!

Franz would need to upgrade to CUPS 1.6 on his server
to get CUPS support for his Mac OS 10.8 clients.

Franz can at most upgrade to CUPS 1.5 on his server
to keep CUPS support for his other clients.

This is a dilemma.

Perhaps Franz could use two servers, one with at most CUPS 1.5
to keep CUPS support for the existing clients and another one
with CUPS 1.6 to get CUPS support for Mac OS 10.8 (and similar)?

Perhaps this way a smooth transition from CUPS <= 1.5
to CUPS >= 1.6 would be possible?


FYI:

Perhaps also mDNS is not yet an ideal solution for bigger networks?

Right now I noticed the Genman heise online news article

http://www.heise.de/newsticker/meldung/Apple-hat-Aerger-mit-Uni-Administratoren-1746990.html

and its English version

http://www.h-online.com/open/news/item/Apple-to-propose-enterprise-standard-for-mDNS-1747124.html

that reads (excerpt):
--------------------------------------------------------------------------
mDNS is incorporated in Apple's Bonjour and in the Avahi software for
Linux to allow small networks to be self-configuring. But mDNS is built
around the idea that everything works on a single subnet. Universities
and businesses that would like to use the technology find that, if they
enable the multicast across their networks, they become flooded
with mDNS traffic.
--------------------------------------------------------------------------

But I am really not a (m)DNS expert - I only noticed those articles.


Kind Regards
Johannes Meixner
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