eth0 won't stay up

[Rick Stevens]

hanfamily at earthlink.net wrote:
> I just reinstalled fedora core 3 to solve the dual boot problem. This time
> I did graphical install so I had a minimal choice so I would have fewer
> packages to remove instead of a text install. I do not know what I did
> different but I created a huge problem with eth0 my log is full of the
> following
> May  4 10:38:05 jupiter kernel: eth0: link up, 100Mbps, half-duplex, lpa 
> 0x40A1
> May  4 10:38:06 jupiter kernel: eth0: link down
> repeated ever fraction of a second. Any ideas what I need to do? I made
> a copy of ifconfig output, route and alot of files in /etc in case they
> would be helpful.

You have a problem with autonegotiation of link speed between your
net card and your switch.  Your best bet is to force both of them to
100Mb, full duplex.

You didn't say what kind of net card you have, nor what the switch is.
If you tell us what the NIC is, we can tell you the options to put
into /etc/modprobe.conf to force it at the Linux side.  You'll have
to consult your user manual for the switch for its commands.

In the meantime, try "ethtool eth0 speed 100 duplex full" and see if
that stops it.
----------------------------------------------------------------------
- Rick Stevens, Senior Systems Engineer     rstevens at vitalstream.com -
- VitalStream, Inc.                       http://www.vitalstream.com -
-                                                                    -
-    "Hello. My PID is Inigo Montoya.  You `kill -9'-ed my parent    -
-                     process.  Prepare to vi."                      -
----------------------------------------------------------------------