Re: NM disconnect after one hour with a wired network

[Dan Williams <dcbw redhat com>]

On Tue, 2011-01-11 at 18:04 +0000, Charles Cultien wrote:
> Le 11/01/2011 16:13, Dan Williams a écrit :
> > On Tue, 2011-01-11 at 12:53 +0000, Charles Cultien wrote:
> >> Le 11/01/2011 02:44, Dan Williams a écrit :
> >>> On Mon, 2011-01-10 at 20:36 +0000, Charles Cultien wrote:
> >>>> Le 10/01/2011 16:35, Larry Finger a écrit :
> >>>>> On 01/09/2011 05:15 AM, Charles Cultien wrote:
> >>>>>> Hi,
> >>>>>> I have a very strange problem :
> >>>>>> I'm connected with the wired network of my university and each time,
> >>>>>> after one hour, Network Manager disconnect himself and didn't reconnect
> >>>>>> automatically. So I have to reconnect by myself evry hour and this is
> >>>>>> boring !
> >>>>>>
> >>>>>> I don't know why and how change this. A dmesg didn't show anything (on
> >>>>>> the moment it disconnect).
> >>>>>>
> >>>>>> I'm using LInux Mint DEbian (so debian testing) with :
> >>>>>> Linux kernel 2.6.32-5-686
> >>>>>> GNOME 2.30.2
> >>>>>> Network Manager 0.8.1
> >>>>>> I'am am behind a proxy (automatically given by the script
> >>>>>> htpp://proxyconf) and so the gnome proxy is configured.
> >>>>>>
> >>>>>> Thank you for helping and didn't hesitate asking for trying something or
> >>>>>> given more information.
> >>>>> Does the listing produced by running 'iw event -t -f' show anything at the time
> >>>>> of disconnect?
> >>>>>
> >>>>> Larry
> >>>>>
> >>>> I run this command : nothing appears before, during and after.
> >>> When the disconnect happens, what does 'dmesg' report at the bottom of
> >>> the output?
> >>>
> >>> Dan
> >>>
> >>>
> >> dmesg didn't show anything.
> >> The only thing showed before any cut (printed only one time) is this line :
> >> [ 1310.768042] CE: hpet increasing min_delta_ns to 15000 nsec
> >>
> >> This can't be coming from my connection because with Windows I haven't
> >> such a cut (or maybe the cut but it reconnect automatically).
> > Can you grab /var/log/messages or /var/log/daemon.log when you note the
> > disconnect and paste/attach the last 100  lines or so?  It could be a
> > DHCP failure too.  If 'dmesg' doesn't say anything it could either be
> > something higher up the stack, or it could just be that your kernel was
> > not build with additional wifi status messages enabled.
> >
> > Dan
> >
> >
> You found something ineteresting!
> Something happened with DHCP (thanks to daemon.log)
> Here one complete cycle from one connection to the end (after I 
> reconnect, etc)
> 
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> Activation (eth1) 
> starting connection 'Auto eth1'
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> (eth1): device state 
> change: 3 -> 4 (reason 0)
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 1 of 5 (Device Prepare) scheduled...
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 1 of 5 (Device Prepare) started...
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 2 of 5 (Device Configure) scheduled...
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 1 of 5 (Device Prepare) complete.
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 2 of 5 (Device Configure) starting...
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> (eth1): device state 
> change: 4 -> 5 (reason 0)
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 2 of 5 (Device Configure) successful.
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 3 of 5 (IP Configure Start) scheduled.
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 2 of 5 (Device Configure) complete.
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 3 of 5 (IP Configure Start) started...
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> (eth1): device state 
> change: 5 -> 7 (reason 0)
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Beginning DHCPv4 transaction (timeout in 45 seconds)
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> dhclient started 
> with pid 9123
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 3 of 5 (IP Configure Start) complete.
> Jan 11 15:50:51 (none) dhclient: Internet Systems Consortium DHCP Client 
> 4.1.1-P1
> Jan 11 15:50:51 (none) dhclient: Copyright 2004-2010 Internet Systems 
> Consortium.
> Jan 11 15:50:51 (none) dhclient: All rights reserved.
> Jan 11 15:50:51 (none) dhclient: For info, please visit 
> https://www.isc.org/software/dhcp/
> Jan 11 15:50:51 (none) dhclient:
> Jan 11 15:50:51 (none) NetworkManager[1618]: <info> (eth1): DHCPv4 state 
> changed nbi -> preinit
> Jan 11 15:50:51 (none) dhclient: Listening on LPF/eth1/00:21:70:6f:42:3a
> Jan 11 15:50:51 (none) dhclient: Sending on   LPF/eth1/00:21:70:6f:42:3a
> Jan 11 15:50:51 (none) dhclient: Sending on   Socket/fallback
> Jan 11 15:50:54 (none) dhclient: DHCPDISCOVER on eth1 to 255.255.255.255 
> port 67 interval 7
> Jan 11 15:50:54 (none) dhclient: DHCPOFFER from 10.193.0.1
> Jan 11 15:50:54 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 15:50:54 (none) dhclient: DHCPACK from 10.193.0.1
> Jan 11 15:50:54 (none) dhclient: bound to 10.193.247.250 -- renewal in 
> 1544 seconds.
> Jan 11 15:50:54 (none) NetworkManager[1618]: <info> (eth1): DHCPv4 state 
> changed preinit -> bound
> Jan 11 15:50:54 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 4 of 5 (IP4 Configure Get) scheduled...
> Jan 11 15:50:54 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 4 of 5 (IP4 Configure Get) started...
> Jan 11 15:50:54 (none) NetworkManager[1618]: <info>   address 10.193.247.250
> Jan 11 15:50:54 (none) NetworkManager[1618]: <info>   prefix 16 
> (255.255.0.0)
> Jan 11 15:50:54 (none) NetworkManager[1618]: <info>   gateway 10.193.0.1
> Jan 11 15:50:54 (none) NetworkManager[1618]: <info>   nameserver 
> '10.132.1.13'
> Jan 11 15:50:54 (none) NetworkManager[1618]: <info>   domain name 'isae.fr'
> Jan 11 15:50:54 (none) NetworkManager[1618]: <info>   wins '10.132.1.2'
> Jan 11 15:50:54 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 5 of 5 (IP Configure Commit) scheduled...
> Jan 11 15:50:54 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 4 of 5 (IP4 Configure Get) complete.
> Jan 11 15:50:54 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 5 of 5 (IP Configure Commit) started...
> Jan 11 15:50:54 (none) avahi-daemon[1510]: Joining mDNS multicast group 
> on interface eth1.IPv4 with address 10.193.247.250.
> Jan 11 15:50:54 (none) avahi-daemon[1510]: New relevant interface 
> eth1.IPv4 for mDNS.
> Jan 11 15:50:54 (none) avahi-daemon[1510]: Registering new address 
> record for 10.193.247.250 on eth1.IPv4.
> Jan 11 15:50:55 (none) NetworkManager[1618]: <info> (eth1): device state 
> change: 7 -> 8 (reason 0)
> Jan 11 15:50:55 (none) NetworkManager[1618]: <info> Policy set 'Auto 
> eth1' (eth1) as default for IPv4 routing and DNS.
> Jan 11 15:50:55 (none) NetworkManager[1618]: <info> Activation (eth1) 
> successful, device activated.
> Jan 11 15:50:55 (none) NetworkManager[1618]: <info> Activation (eth1) 
> Stage 5 of 5 (IP Configure Commit) complete.
> Jan 11 16:16:38 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:16:44 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:17:04 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:17:16 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:17:25 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:17:35 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:17:50 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:18:04 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:18:11 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:18:18 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:18:29 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:18:36 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:18:45 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:18:59 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:19:20 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:19:27 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:19:36 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:19:46 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:19:57 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:20:14 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:20:23 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:20:33 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:20:51 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:21:04 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:21:11 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:21:32 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:21:39 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:21:46 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:21:54 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:22:15 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:22:22 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:22:36 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:22:55 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:23:05 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:23:21 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:23:39 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:23:49 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:24:01 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:24:12 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:24:24 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:24:36 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:24:55 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:25:07 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:25:18 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:25:35 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:25:51 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:26:09 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:26:25 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:26:36 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:26:51 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:27:07 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:27:24 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:27:34 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:27:41 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:27:50 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:28:00 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:28:13 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:28:30 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:28:51 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:29:06 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:29:18 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:29:33 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:29:53 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:30:10 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:30:31 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:30:48 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:31:02 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:31:17 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:31:24 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:31:34 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:31:44 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:31:56 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:32:07 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:32:28 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:32:40 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:32:51 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:33:06 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:33:26 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:33:41 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:33:56 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:34:16 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:34:26 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:34:37 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:34:57 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:35:06 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:35:19 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:35:29 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:35:40 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:35:53 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:36:12 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:36:26 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:36:45 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:36:56 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:37:09 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:37:19 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:37:27 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:37:41 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:37:58 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:38:09 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:38:30 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:38:43 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:38:57 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:39:06 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:39:18 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:39:36 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:39:44 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:40:02 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:40:18 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:40:29 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:40:49 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:40:56 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:41:09 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:41:16 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:41:33 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:41:45 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:42:06 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:42:16 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:42:37 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:42:58 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:43:08 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:43:22 (none) dhclient: DHCPREQUEST on eth1 to 10.193.0.1 port 67
> Jan 11 16:43:33 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:43:45 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:44:03 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:44:17 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:44:32 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:44:49 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:45:02 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:45:15 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:45:25 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:45:39 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:46:00 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:46:21 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:46:29 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:46:45 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:47:00 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:47:14 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:47:34 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:47:51 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:48:02 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:48:18 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:48:32 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:48:40 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:48:53 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:49:08 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:49:23 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:49:37 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:49:50 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:50:05 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:50:19 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:50:33 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:50:40 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:50:49 (none) dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Jan 11 16:50:55 (none) NetworkManager[1618]: <info> (eth1): DHCPv4 state 
> changed bound -> expire
> Jan 11 16:50:55 (none) NetworkManager[1618]: <info> (eth1): device state 
> change: 8 -> 9 (reason 6)
> Jan 11 16:50:55 (none) NetworkManager[1618]: <info> Marking connection 
> 'Auto eth1' invalid because IP configuration expired.
> Jan 11 16:50:55 (none) NetworkManager[1618]: <warn> Activation (eth1) 
> failed.
> Jan 11 16:50:55 (none) NetworkManager[1618]: <info> (eth1): device state 
> change: 9 -> 3 (reason 0)
> Jan 11 16:50:55 (none) NetworkManager[1618]: <info> (eth1): deactivating 
> device (reason: 0).
> Jan 11 16:50:55 (none) NetworkManager[1618]: <info> (eth1): canceled 
> DHCP transaction, DHCP client pid 9123
> Jan 11 16:50:55 (none) NetworkManager[1618]: <error> [1294764655.216071] 
> [nm-system.c:1229] check_one_route(): (eth1): error -34 returned from 
> rtnl_route_del(): Netlink Error (errno = Numerical result out of range)
> Jan 11 16:50:55 (none) avahi-daemon[1510]: Withdrawing address record 
> for 10.193.247.250 on eth1.
> Jan 11 16:50:55 (none) avahi-daemon[1510]: Leaving mDNS multicast group 
> on interface eth1.IPv4 with address 10.193.247.250.
> Jan 11 16:50:55 (none) avahi-daemon[1510]: Interface eth1.IPv4 no longer 
> relevant for mDNS.
> Jan 11 16:50:55 (none) NetworkManager[1618]: <warn> (pid 9123) unhandled 
> DHCP event for interface eth1
> 
> So what to do now ? and thanks to have found where the problem come from !

There's two reasons for the DHCP expiry:

1) the driver for your ethernet card has a bug, and fails to transmit or
receive properly after a while

2) your DHCP server is, for some reason, refusing to reply to your
renewal requests

When the DHCP lease expires, NM *must* tear down the connection as it's
no longer valid to keep that IP address.

Dan