[Discuss] wired network broken

[Alan W. Irwin]

On 2009-10-01 17:08-0700 John Blomfield wrote:

> The network wired connection on my desktop computer has suddenly stopped working.  I am running Debian 5, KDE 3.5.10 and knetworkmanager/NetworkManager.  The only thing that may have caused this was that I tried a RIP CD for the first time as I hadn't used this tool before. This may be just coincidence.
>
> The ethernet NIC is detected ok and is enabled but it seems that dhcp is not working.  I tried a couple of live CD's (Fedora and Ubuntu) and neither managed to get an IP address.  However, I returned to RIP using the X interface and running its "setup network connection" produced an IP of 169.254.244.159 and my router is 192.168.0.100 - 254 for dhcp and manual 192.168.0.2 - 99.  When I ran the set up again it produced the correct reserved IP of 192.168.0.104. I then returned to Debian but it still did not work.  Back again to RIP the first try failed and the second worked.
>
> Any ideas anyone?

Sometimes equipment works differently depending on whether you do a soft
reboot (where the power remains on during the reboot) or a hard reboot. In
the former case you use "shutdown -r now". In the latter case you halt the
computer and power it off with "shutdown -h now" and also power off all
auxiliary networking equipment (if you have any).  Then, you also pull the
plug on everything (since often power switches do not really stop all power
from getting to the equipment).  Then plug-in, power on, and boot.

I don't think you can call it a hard reboot unless the power is completely
cut (e.g., by pulling the plug from the wall).  If you are keeping a diary
of important computer hardware events (which you should probably do in any
case), it is a good idea to mention whether any particular reboot is soft or
hard. For example, if you were the victim of one of the extended power
outages this summer, that would have caused a hard reboot.

For soft reboots there is a chance that equipment remembers bad (or good)
values from the previous time.  So for example, you might have to do a hard
reboot to RIP to establish proper networking then soft reboot after that to
get Debian to work.  Or maybe hard reboot for both cases because of some
conflict between the two concerning the state in which they leave your
networking hardware.  Anyhow, it is worth it to try some experimentation
with both soft and hard rebooting.

Note, this is one of those deals where it is probably a long shot but worth
a try.

Alan
__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state implementation
for stellar interiors (freeeos.sf.net); PLplot scientific plotting software
package (plplot.org); the libLASi project (unifont.org/lasi); the Loads of
Linux Links project (loll.sf.net); and the Linux Brochure Project
(lbproject.sf.net).
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Linux-powered Science
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