RHEL v.5 eth0 drops, only unplug/replug of cable fixes it

lokke · 07-11-2007, 12:40 PM

i am running a fresh installation of red hat enterprise linux v.5 on a dell dimension 8200 desktop box (all stock hardware, including the ethernet card included with it.)

i installed RHEL v.3 and had no issues with connectivity, but wanted to get going with the latest version of RHEL if i can make it work. i also booted off of a live CD and made sure that the problem wasn't hardware related (cable, jack, card, etc) it worked fine off the live CD.

the symptom: cannot connect to the net, internal or external. pings to the router find no route to host. if the ethernet cable is unplugged and replugged, the connection comes up, and everything is great (web access is fine, pings to the router go through just fine) but after 2-3 minutes the connection drops. the only way to get it back is to unplug/replug the cable, then the cycle starts again.

the system log shows the following activity:

kernel: xenbr0: port 2(peth0) entering learning state <-- after the cable is unplugged/replugged
kernel: xenbr0: topology change detected, propagating
kernel: xenbr0: port 2(peth0) entering forwarding state
kernel: xenbr0: port 2(peth0) entering disabled state

then the connection is dropped.

i managed to get the system updater to run, by unplugging/replugging the cable every 2 minutes while all the patches and upgrades were downloaded, and got them to update the system. problem still exists.

found the following page talking about a bug with xen:

http://bugzilla.xensource.com/bugzil...bug.cgi?id=431

tried setting the interface to not bind to a specific MAC as suggested... no change.
tried disabling the firewall as suggested. no change.

has anyone seen this before? i can't call red hat support as this is an educational license and i have not paid the extra $$ for support (yet)

if i can make this server work then i will buy a real server class machine to run it on, and buy a version with support, but i can't get past this pitfall.

lokke · 07-13-2007, 11:06 AM

no one else has seen this problem?

jeenam · 07-13-2007, 11:10 AM

What is the model of the ethernet interface? Run an lspci or lspci -v output. Sounds like a module problem.

lokke · 07-13-2007, 11:45 AM

output from lspci:

00:00.0 Host bridge: Intel Corporation 82850 850 (Tehama) Chipset Host Bridge (MCH) (rev 04)
00:01.0 PCI bridge: Intel Corporation 82850 850 (Tehama) Chipset AGP Bridge (rev 04)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 04)
00:1f.0 ISA bridge: Intel Corporation 82801BA ISA Bridge (LPC) (rev 04)
00:1f.1 IDE interface: Intel Corporation 82801BA IDE U100 (rev 04)
00:1f.2 USB Controller: Intel Corporation 82801BA/BAM USB (Hub #1) (rev 04)
00:1f.3 SMBus: Intel Corporation 82801BA/BAM SMBus (rev 04)
00:1f.4 USB Controller: Intel Corporation 82801BA/BAM USB (Hub #2) (rev 04)
00:1f.5 Multimedia audio controller: Intel Corporation 82801BA/BAM AC'97 Audio (rev 04)
01:00.0 VGA compatible controller: nVidia Corporation NV11 [GeForce2 MX/MX 400] (rev b2)
02:08.0 Communication controller: Agere Systems LT WinModem (rev 02)
02:09.0 Ethernet controller: Davicom Semiconductor, Inc. 21x4x DEC-Tulip compatible 10/100 Ethernet (rev 31)

lokke · 07-13-2007, 12:09 PM

ok, i fixed it after searching this site for that ethernet controller.

found a link to this thread on an ubuntu forum:

http://ubuntuforums.org/showthread.php?t=186430

Quote:

The solution to fix this is relatively easy. It's made up of only 2 steps.

First, you need to add dmfe to /etc/modules. To do this you need to open up modules with gedit by typing the following code into a terminal.

Code:

sudo gedit /etc/modules

Then, you need to add "dmfe" to this, without the quotes. Make sure you save.

Finally, you need to blacklist the tulip driver so it wont run at startup. To do this you need to run the following in a terminal.

Code:

sudo gedit /etc/modprobe.d/blacklist

After this is opened, you need to add "blacklist tulip", without the quotations, somewhere in the file. Then save.

worked for me. thanks for the push in the right direction