System Drops Network Connection

Jay Ridgley jridgley2 at
Wed Dec 25 12:58:58 UTC 2013

On 12/24/2013 08:20 AM, Jay Ridgley wrote:
> On 12/24/2013 03:22 AM, Colin Law wrote:
>> On 24 December 2013 09:17, Jay Ridgley <jridgley2 at> wrote:
>>> Folks,
>>> Recently one of my systems started dropping the connection to my network. If
>>> I reboot the system it is up for a while as long as no one is doing anything
>>> on it(no logins and no printing) but it will drop the connection after a
>>> time. My gut feel is that Network Manager is causing the problem but I do
>>> not know where to look to find the problem.
>>> There has been no changes made for the configuration files yet this happens.
>>> I have found some information with Google about this type of problem but I
>>> have not been able to find a solution.
>>> I use a static wired connection to my network.
>>> System is running Ubuntu 12.04.3 LTS (GNU/Linux 3.2.0-57-generic i686) all
>>> updates have been applied.
>>> I have two systems that are configured in the same manner one has no
>>> problems the other does. Any ideas?
>> Anything in /var/log/syslog?
> There are several entries for Network Manager reporting Unmanaged Device found
>> When you say it goes down, do you mean it says it is disconnected or
>> just is not working?
> It remains working, however, there is no connection to the network. Can not ping
> for example.
>> What happens if you unplug the cable and put it back?


Merry Christmas!

Sorry to take so long

> Have not tried that, yet

This morning I unplugged the cat 5 cable and plugged it back in and the system 
connected to the network. I was also able to ping & (as 
Paul Cartwright suggested - I do NOT think it is a DNS problem) (see below)

Yesterday I monitored the system after I had reinstalled Network Manager using 
synaptic and rebooted the system.

I used an ssh connection from another system and started running:
tail -f /var/log/syslog

That was working fine on an idle system until:

Dec 25 00:17:01 ursa CRON[2802]: (root) CMD (   cd / && run-parts --report 
Write failed: Broken pipe

I was asleep and did not see the results until I got up this morning...
I was able to restart the ssh connection successfully.

/var/log/syslog continued to record events just like that shown above (cron 
entries) until about 06:14 then there are several entries. It shows the NIC 
being unplugged and the network restarting...

I will continue to monitor...




Jay Ridgley
jridgley2 at
Registered Linux User ID - 9115
Registered Ubuntu User ID - 23320

More information about the ubuntu-users mailing list