The CUPS server could not be contacted.

SiriusB · 9 Jul 2007 at 02:55

Arrrrgh!!!

OK, with that out the way, down to business.

For some reason my Ubuntu Feisty Fawn install suddenly throws "The CUPS server could not be contacted." at me whenever I try to access the System > Administration > Printing page.

It worked just fine a day or two ago. Now it doesn't.

The only thing I have changed was the installation of SWAT. Perhaps something I did there messed up the CUPS program... or something.

I removed and reinstalled samba and anything releated to cups and cupsys.

I have tried EVERYTHING I have found with a Google search of "The CUPS server could not be contacted."

I am at a complete loss. I really do not want to have to reinstall as that would be a monumental pain in the arse.

All help welcomed

M0KUJ1N · 9 Jul 2007 at 08:40

First off, is cups actually running on your machine? Is there anything showing up in the cups logs? Is it listening on port 631? (doing netstat -antp | grep 631 should confirm this).

Also does running cupsd from the commandline as:

/usr/sbin/cupsd -f -c /etc/cupsd/cups.conf

generate any output?

Finally I found a cached experts exchange thread that suggested this problem was caused by SWAT upgrading libraries and upgrading to the latest version of CUPS fixed it.

SiriusB · 9 Jul 2007 at 11:42

aeternum@windwardx$ sudo ps ax | grep "cups"
10533 ? Ss 0:00 /usr/sbin/cupsd

So cupsd appears to be running.

aeternum@windwardx$ sudo netstat -antp | grep 631
tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN 10533/cupsd

Again, it appears to be running.

aeternum@windwardx$ sudo /usr/sbin/cupsd -f -c /etc/cupsd/cupsd.conf
Message from syslogd@windwardx at Mon Jul 9 11:37:09 2007 ...
windwardx cupsd: Unable to read configuration file '/etc/cupsd/cupsd.conf' - exiting!

OK now there appears to be some problem... There is definitely a cupsd.conf file and the path to it is correct. The contents of the cupsd.conf also appear to be correct [no obvious errors/corruption.]

Finally I found a cached experts exchange thread that suggested this problem was caused by SWAT upgrading libraries and upgrading to the latest version of CUPS fixed it.

I have completely removed CUPS, Samba and Swat [using purge option] and reinstalled Samaba and CUPS fresh. Everything is at the latest version [according to Synaptic].

Bes · 9 Jul 2007 at 13:36

Is your virtual network device set up ok? Do you have any IP loopback configuration issues? Normally a symptom of this is other GUI tools like the console taking ages to open.

SiriusB · 9 Jul 2007 at 16:44

Is there any definitive test I can use to check my virtual network devices?

Seeing if my Terminal opens quickly [which it does] or not seems a rather inconclusive way of going about it

M0KUJ1N · 9 Jul 2007 at 20:19

Can you access the CUPS web interface at localhost:631?

Bes · 9 Jul 2007 at 22:06

I had an issue with my IP loopback at first and certain applications failing to load... Make sure it is in this format:

Code:

[sam@sam foldingathome]$ more /etc/hosts
#
# /etc/hosts: static lookup table for host names
#

#<ip-address>   <hostname.domain.org>   <hostname>
127.0.0.1               localhost.localdomain   localhost sam

# End of file

SiriusB · 9 Jul 2007 at 22:40

M0KUJ1N said:
Can you access the CUPS web interface at localhost:631?

The last time I tried [earlier today] I could. I am not at my linux machine at this exact moment though so I can't tell you for sure.

@Bes

I will check that too in a little while when I am at the linux machine.

SiriusB · 10 Jul 2007 at 11:24

OK

Just had a look now and http://localhost:631/ does give me access to a config page. Just had a little mess about and it appears it would let me add a printer. Not actually tried yet as 1: my printer isn't listed and 2: the options are a little confusing. However, the main thing is I can actually access it.

Make me wonder why going System > Admin > Printing doesnt work!

As for my hosts file:

aeternum@windwardx:~$ cat /etc/hosts
127.0.0.1 localhost
127.0.1.1 windwardx

# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts

It looks different to your example. Could it be a disto-related difference or is it knackered in some way?

SiriusB · 10 Jul 2007 at 14:12

HURRAH!

I have solved it! And it was a very silly trivial thing too!

My printer was installed as a network printer, however the print server wasn't running so no longer existed as far as my CUPS/drivers were concerned!

Just deleted the ServerName line in my client.conf and all is well.

Just need to remember how I managed to install the printer in the first place