I have two computers, one with a HP printer on it and one with a Samsung printer on it.
Both systems have their respective pritnters listed under system-config-printer and have "enabled" "accepting jobs" and "shared" checked.
Up to a few days ago this worked fine. Suddenly I can't see either printer from the other machine and as far as I know nothing has changed other than the usual "yum update" stuff that has come in over the past few days. I can see the local printer on each computer but system-config-printer (and applications) can't see the remote printer at all.
It's odd that the remote printer has disappeared from both computers at the same time. Each computer can see its own local printer but it can't see the remote printer on the other computer.
The firewall has port 631 tcp and udp both allowed on both computers. The cups version on both computers is cups-1.3.7-26.el5_6.1 which doesn't appear to have been updated since April.
Creating a new printer with system-config-printer seems to work. "new printer" "IPP", "generic postscript driver". Print test page. Test page printed.
So it's just the automatic find-the--remote-printer function that's not working.
I have avahi-daemon disabled on both of these computers? Is that the problem? I re-enabled it on both computers and it didn't seem to change anything; it still didn't see the remote printers.
Frank Cox wrote:
Creating a new printer with system-config-printer seems to work. "new printer" "IPP", "generic postscript driver". Print test page. Test page printed.
So it's just the automatic find-the--remote-printer function that's not working.
I have avahi-daemon disabled on both of these computers? Is that the problem? I re-enabled it on both computers and it didn't seem to change anything; it still didn't see the remote printers.
Have you rebooted after the updates?
Ljubomir
On Sat, 02 Jul 2011 01:07:45 +0200 Ljubomir Ljubojevic wrote:
Have you rebooted after the updates?
What updates?
I started avahi-daemon on both computers, restarted cups on both computers.
Nothing changed -- Still didn't see the remote printers.
I've had avahi-daemon turned off on these computers for a long time and it hasn't been a problem before so it was just a shot in the dark anyway, and it apparently didn't pan out.
On Fri, 2011-07-01 at 17:15 -0600, Frank Cox wrote:
On Sat, 02 Jul 2011 01:07:45 +0200 Ljubomir Ljubojevic wrote:
Have you rebooted after the updates?
What updates?
I started avahi-daemon on both computers, restarted cups on both computers.
Nothing changed -- Still didn't see the remote printers.
I've had avahi-daemon turned off on these computers for a long time and it hasn't been a problem before so it was just a shot in the dark anyway, and it apparently didn't pan out.
---- you should do the logical things before you waste your time with shots in the dark but I think avahi is a very useful tool for some things.
Logs? /var/log/cups/error_log
Settings? /etc/cups/printers.conf & cupsd.conf
Ping?
Telnet from client? telnet $CUPS_SERVER 631
restart cups service lately?
service cups restart
Craig
On Fri, 01 Jul 2011 21:10:36 -0700 Craig White wrote:
Logs? /var/log/cups/error_log
Nothing of note.
Settings? /etc/cups/printers.conf & cupsd.conf
Nothing changed from when it did work before.
Ping?
Network connectivity is fine.
Telnet from client? telnet $CUPS_SERVER 631
Cups is communicating -- entering the printer directly makes it work. It's just the automatic detection that's not working.
restart cups service lately?
Restarted on both computers. No change.
Frank Cox wrote:
On Fri, 01 Jul 2011 21:10:36 -0700 Craig White wrote:
Logs? /var/log/cups/error_log
Nothing of note.
Settings? /etc/cups/printers.conf & cupsd.conf
Nothing changed from when it did work before.
Ping?
Network connectivity is fine.
Telnet from client? telnet $CUPS_SERVER 631
Cups is communicating -- entering the printer directly makes it work. It's just the automatic detection that's not working.
restart cups service lately?
Restarted on both computers. No change.
Is there "browsable" boolean like in Samba? I never had to set up printers in Linux network.
Ljubomir
On Saturday 02 Jul 2011 07:37:20 Frank Cox wrote:
On Fri, 01 Jul 2011 21:10:36 -0700
Craig White wrote:
Logs? /var/log/cups/error_log
Nothing of note.
How about after you do:
sudo cupsctl --debug-logging
and run with it for a while?
Settings? /etc/cups/printers.conf & cupsd.conf
Nothing changed from when it did work before.
Although you said CUPS wasn't updated so it should be unlikely, but may be worth re-applying settings to enable sharing (on server) and browsing (on client). Have a look at:
http://www.cups.org/documentation.php/doc-1.4/sharing.html
and man cupsctl(8) which has handy options like --share-printers and --remote- printers.
Also, if you're still having problems see what's in the remote cache file: /var/cache/cups/remote.cache; if it seems stale remove it and restart cups.
On Mon, 4 Jul 2011 09:55:18 +0100 Michael Gliwinski wrote:
Although you said CUPS wasn't updated so it should be unlikely, but may be worth re-applying settings to enable sharing (on server) and browsing (on client).
I actually removed and reinstalled the printers with system-config-printer on each machine, with no change.
At this point I've decided to give up on it for the moment since the remote printers do work as long as I configure them manually on each machine. I plan to update both machines to Centos 6 and hopefully the problem will just go away at that point.
A huge thank you to everyone who replied with suggestions! And a further thank you to everyone who thought about this problem, even if you didn't reply. Your time thinking about it is also appreciated.
I sincerely appreciate the huge depth of knowledge that's represented on this mailing list.
Frank Cox wrote:
On Sat, 02 Jul 2011 01:07:45 +0200 Ljubomir Ljubojevic wrote:
Have you rebooted after the updates?
What updates?
I started avahi-daemon on both computers, restarted cups on both computers.
Nothing changed -- Still didn't see the remote printers.
I've had avahi-daemon turned off on these computers for a long time and it hasn't been a problem before so it was just a shot in the dark anyway, and it apparently didn't pan out.
From your original posts: Frank Cox wrote: Up to a few days ago this worked fine. Suddenly I can't see either printer from the other machine and as far as I know nothing has changed other than the usual "yum update" stuff that has come in over the past few days. I can see the local printer on each computer but system-config-printer (and applications) can't see the remote printer at all. Since there were updates of various important packages, I thought rebooting after updates might be a good thing, just in case.
Ljubomir
On Sat, 02 Jul 2011 20:42:47 +0200 Ljubomir Ljubojevic wrote:
Since there were updates of various important packages, I thought rebooting after updates might be a good thing, just in case.
I rebooted after the glibc update the other day. I even tried rebooting when I first noticed that the remote printers had disappeared just-in-case, but nothing changed.
Is there "browsable" boolean like in Samba? I never had to set up printers in Linux network.
Up to this point remote printers just show up by magic on the list of available printers as long as they are marked as "shared" on the host machine. Now they don't show up on the list of available printers on the remote machine, even though they are available and shared on the host machine.
But installing the remote printer as an IPP printer on the client machine through system-config-printer and specifying the hostname and printer name on the host works, and the printer can be used.
Somewhere along the line either whatever it is on the server machine that announces an available printer on the network or whatever it is on the client machine that finds that printer and adds it to the list of available printers has stopped working, on two computers which are each a cups host and a client of the other.
On Sat, 2011-07-02 at 12:50 -0600, Frank Cox wrote:
On Sat, 02 Jul 2011 20:42:47 +0200 Ljubomir Ljubojevic wrote:
Is there "browsable" boolean like in Samba? I never had to set up printers in Linux network.
Up to this point remote printers just show up by magic on the list of available printers as long as they are marked as "shared" on the host machine. Now they don't show up on the list of available printers on the remote machine, even though they are available and shared on the host machine.
---- I think what he meant was to check /etc/cups/cupsd.conf for...
# Show shared printers on the local network. Browsing On BrowseOrder allow,deny # (Change '@LOCAL' to 'ALL' if using directed broadcasts from another subnet.) BrowseAllow @LOCAL
Craig
On Sat, 02 Jul 2011 12:32:02 -0700 Craig White wrote:
I think what he meant was to check /etc/cups/cupsd.conf for...
# Show shared printers on the local network. Browsing On BrowseOrder allow,deny # (Change '@LOCAL' to 'ALL' if using directed broadcasts from another subnet.) BrowseAllow @LOCAL
cupsd.conf on both machines matches what you posted here.
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Craig White -
Frank Cox -
Ljubomir Ljubojevic -
Michael Gliwinski