When a CUPS client system is not able to access port 631 of the server machine listed in client.conf, programs on the client machine, which are dependent on CUPS such as gnome-cups-manager and firefox print dialog, become unresponsive and crash.
Steps to reproduce:
configured your network with shared printing.
Instructions on setting up shared printing can be found here: http://occy.net/printing.
Edit your client machine's client.conf file to include the address/name of your Print Server
close the 631 port on your server machine.
Open the cups-manager on your client machine
Observe that cups-manager crashes
Attempt to print a page from Firefox from your client machine
Observe that Firefox hangs and or crashes
(In reply to comment #0)
> I configured my network with shared printing. I found out that I had not opened
> the right ports on my print server, but the real problem was that cups-manager
> hanged
This is really a problem of how TCP is designed. If you completely block packets
to the right port, your computer will not get any ICMP message that the port is
invalid, and thus will get the usual 30 second timeout. Does it recover after 30
seconds?
> and even crashed Firefox when I tried to print a page
That's more serious. That means you tried to print something in Firefox?