How can I REALLY disable a NIC?

ap0calypse · 07-08-2009, 02:42 AM

g'morning guys

I have the following problem which I can't figure out to solve it.
I know how to disable a NIC with ifconfig or ip, but the problem is that our cisco router still "sees" the NIC as connected.

A colleague told me, that Windows could actually really disable the device by powering it off. It then appears as "not connected" for the router. But this doesn't happen by just typing in ifconfig eth0 down or ip link set dev eth0 down. Both commands work fine, but the router still detects the NIC as connected.

I also thought of unloading the module, but I don't know if that's the only possibility. Could someone tell me if and how this is possible?

Thanks in advance!

Febi881 · 07-08-2009, 03:08 AM

you need to disable the NIc from bios if it is on-board otherwise unplug the network cable.

Quote:

Originally Posted by ap0calypse

g'morning guys

Iodule, but I don't know if that's the only possibility. Could someone tell me if and how this is possible?

Thanks in advance!

ap0calypse · 07-08-2009, 03:21 AM

Well, that's not really a satisfying answer. Is there really no possibility that works "online"?

centosboy · 07-08-2009, 03:25 AM

have you tried something like

Code:

perl -pi -e's/ONBOOT=yes/ONBOOT=no/' /etc/sysconfig/network-scripts/ifcfg-ethxx

and then a network restart?

ap0calypse · 07-08-2009, 03:32 AM

You don't get my problem :P I just want to make one of my NICs more or less "powerless" (switch off the link).
I just can't accept that Windows can do this an Linux can't ... I don't want to believe this!

centosboy · 07-08-2009, 03:37 AM

hmmm...apart from unaliasing the driver and restarting the network...

Code:

less /etc/modprobe.conf
alias eth0 e1000
alias eth1 e1000
alias scsi_hostadapter ata_piix

zhjim · 07-08-2009, 03:44 AM

unload the driver modprobe -r drivername
set the power to zero with ACPI/APM like this

Get the device to shutdonw

Code:

lspci

echo 0-3 into the sys file

Code:

echo 3 > /sys/bus/pci/devices/num_of:your:device/power/state

And the nic should be gone. to reenable just echo 0 to the file. Not quite sure of the numbers. All taken from http://files.opensuse.org/opensuse/e...opendesign.pdf

Cheers Zhjim

zhjim · 07-08-2009, 03:46 AM

Heres a nother link that might be helpful
http://www.gentoo.org/doc/en/power-management-guide.xml

ap0calypse · 07-08-2009, 04:05 AM

Thanks zhjim, I guess this could possibly help me out.
At first I tried it with simple echo, but after an error message i figured out that it had to be "echo -n"

I'll talk to my colleague to test it now.

Thanks so far!