Re: How long until a deleted printer actually vanishes?
On Fri 25 Jan 2019 at 16:27:36 +0100, Marc Haber wrote:
> Hi,
Hello Marc.
> in my overengineered home network, I have
>
> - a VLAN with my Laser Printer and an Inkjet.
> - another VLAN with my CUPS server, parada, running Debian stable
> - another VLAN with my desktop workstation, fan, running Debian
> unstable and KDE.
> - a router/firewall, barrida, running a packet filter and avahi-daemon
> in reflector configuration.
I have no knowledge or experience of VLANs or reflectors but I will
give my interpretation of what the setup does. Please correct it if
necessary.
The Lexmark and Inkjet have queues configured on parada. These queues
are advertised and seen by fan. They get enumerated by print dialogs
on fan. Essentially, parada is the server and fan the client.
> The printer is configured to do avahi/zeroconf, parada and fan both have
> avahi-daemon installed and running, and both also have cups-browsed
> installed and running. The ultimate goal is to be able to print from
> Linux, from Windows and from iOS devices. Unfortunately, this has not
> been successful so far, sometimes part of the functions work, sometimes
> not.
parada doesn't need cups-browsed unless you want it to do the old CUPS
broadcasting (which I suspect you don't). Employing it on fan is
optional; please see the wiki.
> For debugging, I have deleted all printer definitions from fan's CUPS
> server and all but the Inkjet definition from parada's CUPS server.
>
> As I read on the wiki, GTK applications get their printer list from
> avahi, so I'd have expected the printer list presented by evince to be
> empty but the Inkjet. However, it shows the Inkjet and one old entry for
> the Laser Printer ("c534-ka51 Lexmark C534-KA51 on parada"). I guess
> that one is a leftvoer from the deleting procedure.
You have cups-browsed running, so I would expect two Inkjet entries. One
due to direct interaction with the DNS-SD broadcasts from parada and the
other because cups-browsed automatically sets up a local queue.
> Which daemons (cups? cups-browsed? avahi?) on which hosts do I restart
> to have the old printer entry vanish? Or, alternatively, how long do I
> have to wait until those entries time out eventually?
Stop CUPS on parada; the Inkjet entry(ies) should disappear from Evince.
What happens to c534-ka51 Lexmark C534-KA51 on parada? Restarting CUPS
should see Inkjet reappear almost instantaneously in Evince.
Now stop CUPS on fan (this also stops cups-browsed). What happens in
Evince?
> Another question, will my Lexmark C534 (it can do Postscript, prints PDF
> uploaded via ftp and alot more, but does not do AirPrint by itself) be
> eligible for driverless printing?
No. It doesn't use DNS-SD broadcasting.
> Would it be helpful in any way to upgrade parada to buster? Usually I
> keep my infrastructure systems on Debian stable, but I can make an
> exception here if that is actually helpful
Not that I can think of immediately.
Regards,
Brian.
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