Intermittent loss of network connection problem with Lucid

[NoOp]

On 05/08/2010 05:27 AM, Graham Watkins wrote:
> Good day all,
> 
> I've been running Lucid for about a week now and am mostly happy with 
> its performance. There are a couple of minor niggles that I wonder if 
> anyone here can advise me on.
> 
> 1.    The network connection occasionally goes down.  This generally 
> happens after a reboot.  It is fixable by shutting down the computer and 
> switching off the modem for a minute or so and then restarting.  I would 
> have suspected my modem but for the fact that it has only started 
> happening since I installed 10.4 last Saturday.
> 
> when the connection is active, ifconfig shows:
> eth1      Link encap:Ethernet  HWaddr 00:1e:8c:0d:79:43
>            inet addr:82.4.159.236  Bcast:82.4.159.255  Mask:255.255.252.0
>            inet6 addr: fe80::21e:8cff:fe0d:7943/64 Scope:Link
>            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>            RX packets:1419 errors:0 dropped:0 overruns:0 frame:0
>            TX packets:1470 errors:0 dropped:0 overruns:0 carrier:0
>            collisions:0 txqueuelen:1000
>            RX bytes:1090211 (1.0 MB)  TX bytes:271931 (271.9 KB)
>            Interrupt:20 Base address:0x6000
> 
> when the connection is not working I get:
> graham at graham-desktop:~$ ifconfig
> eth0      Link encap:Ethernet  HWaddr 00:00:00:00:79:43
>            UP BROADCAST MULTICAST  MTU:1500  Metric:1
>            RX packets:0 errors:0 dropped:0 overruns:0 frame:0
>            TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
>            collisions:0 txqueuelen:1000
>            RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
>            Interrupt:20 Base address:0x8000
> 
> 
> It would seem that eth0 is a non-existent connection and it doesn't take 
> a computer genius to see that the problem lies here somewhere. Any 
> suggestions?

First place I'd check is your modem logs. Are you seeing any errors there?

It sounds as if dhclient isn't releasing when your isp issues you a new
lease; next time it goes down try this:

$ sudo dhclient -r
$ sudo dhclient
or
$ sudo dhclient eth1

Then check:
$ sudo ifconfig -a

Note: your seeing the 'eth0' because eth1 hasn't gotten an ip from your
modem - that part is normal.