A CUPS print server experience.

[akonstam at trinity.edu]

I am posting this short record of my fight to configure a cups print
server and print client over the last week, If you don't care about
this topic just skip this message.

The horror story started last Monday when I had configured a FC3 print
server to allow printing to 6 HP printers. All were configured using
the CUPS web interface using the lpd protocol. The client was
configured using the Automatic Configuration of printers on a client
by not doing any configuration on the client except placing the name
of the print server in the /etc/cups/client.conf file on the client.
It was working as far as I could tell to print text. ps. and pdf
files.

Tuesday at 10 am the roof fell in on my configuration. No printing
worked from the client. Worst of  every entry in the CUPS web
interface list of printers said: To configure this printer use
system-config-printer. Also most of the entries in the configuration
had been destroyed, in particular, the device driver for the printers
had been changed.

Well the CUPS system administration document says automatic
configuration of client printers is not supported by LPD printers. So
why did the system work the day before. Well the documentation is old
or in error. Automatic Configuration works for LPD printers under CUPS.
Ok that was not the problem.

Eventually, I found that is you set up printers  using the CUPS
web interface and then open up system-config-printer there is a good
chance that your CUPS web configurations will be ruined. This happened
to me three times so believe me it can happen. I would rename
system-config-printer so it can't be executed.

The final matter is really not a mystery but in my frustration of
having the system self-destruct I messed up the cupsd.conf file. I
know no one else would do the stupid things I did :-)
The cupsd.conf file needs the following two entries made. The rest can
be ignored most of the time:
<Location />
Order Deny,Allow
Deny From All
Allow From <the address of your subnet>  <-- formats given in the file.
</Location>
and
Listen <name of your server>  <-- formats given in the file.

On the client client.conf should contain the line:

ServerName myhost.domain.com   <-- name of print server.

As I said before this is the way to configure print servers and
clients, once you understand what you are doing.

For example, we have about 50 print clients. Now when we add a new
printer to the server we need do nothing on the clients and printing
will work.
-- 

-------------------------------------------
Aaron Konstam
Computer Science
Trinity University
telephone: (210)-999-7484