Detection of printers in FC4

[Guy Fraser]

On Fri, 2005-07-01 at 11:08 -0500, gslink wrote:
> Tim Waugh wrote:
> > On Fri, Jan 07, 2005 at 09:28:18AM -0500, gslink wrote:
> > 
> > 
> >>FC3 (I need a more stable system than Rawhide) has about the correct 
> >>printing detection.  What happens if you have several hundred printers 
> >>on a network.  You do not want detection as these are likely to be light 
> >>duty, private printers. 
> > 
> > 
> > Why would private printers be being broadcast in the first place?
> > 
> > 
> >>Currently, CUPS publishes those printers that are marked shared
> >>queue and these are picked up by all machines on the network.  This
> >>is fine but searching for and publishing printers that just have a
> >>lan address is wrong.  On a large lan this could take hours and
> >>result in a long printer listing.
> > 
> > 
> > I'm not quite sure what behaviour you are seeing that you think is
> > incorrect.  Could you be a bit more specific please?
> > 
> > Tim.
> > */
> I see nothing that I think needs to be changed.  In replying to a 
> request to change how printers are picked up I merely point out that 
> CUPS allows connection in many ways.  Only those printers where specific 
> action has been taken should be picked up without intervention.  I know 
> of an installation that has several hundred printers that are directly 
> lan connected.  These printers use JetDirect.  Others use Novell, or

That is the Network administrators fault, not Linux or FC3.

>  
> Unix.  In most cases you do not want these printers to be public but 
> they are.  You don't want Linux to search for them.  CUPS finds public 

If the network was designed properly, then yes I would.

> printers now but only those that are declared public by CUPS.  I believe 
> the whole business should be left the way it is.  Before someone asks 
> for it, you can share printers over a lan without implementing any other 
> kind of lan connection.

Windows, Appletalk/Ethertalk, Jetdirect and Novell sharing systems are 
"chatty" and should be avoided in large numbers on a network segment.
These protocols use IP,IPX,DDP and/or Ethernet broadcasting to announce 
themselves on a regular basis. I have seen situations where networked 
printers and fax machines have rendered networks useless due to there
constant "bleating". 

If possible a static IP address and only LPR should be configured on
network printers. If they need to be shared on other protocols then 
they should be setup to be shared from a file or print server and there 
should only be one file server and or print server per work-group.

Segregating work-groups helps to keep the broadcast traffic down and
improves network efficiency.

I have worked on many different kinds of networks using different 
topologies and protocols for over 20 years now. For the past 9 years 
I have maintained a very large group of networks. Good network design 
requires a lot of hard work to setup, and is not plug and play. For 
small segregated networks plug and play is fine and works well, but 
for medium to large networks plug and play will cause you more trouble 
than it would take to just take time to set things up properly the 
first time. Eight years ago I setup a Linux machine to act as a 
file and print server for all our Apple, Windows and Unix workstations
and all our Unix and new Linux Servers. It was difficult to setup at 
the time, but extended the life of our local 10b2 LAN. Of course now 
it's all 100bT, 1000bT and Fibre but we still only need one file and 
print server. 

Proper network design can simplify your network and improve it's 
performance.