CentOS - Feb 2020 - CentOS 7 : network interface renamed from eth0 to eth1 after reboot

Hi,

I've done my fair share of CentOS 7 installations, but this is the first
time I
have this kind of weird problem. Here goes.

In my office I have a battered Dell Optiplex 320 PC with two NICs that I'm 
using as a bare metal sandbox server for testing purposes.

The CentOS 7 installer sees the connected network card as eth0. But after the 
first reboot, the interface comes up as eth1.

My first reflex was to rename ifcfg-eth0 to ifcfg-eth1 and edit it accordingly. 
Weirdly enough, on the subsequent reboot the interface comes back as eth0.

I took a peek in /etc/udev/rules.d to see if there was any persistent interface 
definition, but the directory is empty.

On a side note, I installed Ubuntu Server 16.04 LTS on that same machine and 
got the exact same problem. Debian installer sees the main network interface as 
eth0, but on the first reboot the interface comes back as eth1.

Any suggestions ?

Niki

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Very strange and as you suggested delete the ifcfg-eth0 file and recreate,
specify your settings. I suspect your wireless device and or systemboard is
faulty. Is there a BIOS hardware self-test you could perform to check the
integrity of your hardware?

On Sun, Feb 9, 2020, at 8:10 AM, Nicolas Kovacs wrote:
> Hi,
> 
> I've done my fair share of CentOS 7 installations, but this is the
first time I
> have this kind of weird problem. Here goes.
> 
> In my office I have a battered Dell Optiplex 320 PC with two NICs that
I'm
> using as a bare metal sandbox server for testing purposes.
> 
> The CentOS 7 installer sees the connected network card as eth0. But after
the
> first reboot, the interface comes up as eth1.
> 
> My first reflex was to rename ifcfg-eth0 to ifcfg-eth1 and edit it
accordingly.
> Weirdly enough, on the subsequent reboot the interface comes back as eth0.
> 
> I took a peek in /etc/udev/rules.d to see if there was any persistent
interface
> definition, but the directory is empty.
> 
> On a side note, I installed Ubuntu Server 16.04 LTS on that same machine
and
> got the exact same problem. Debian installer sees the main network
interface as
> eth0, but on the first reboot the interface comes back as eth1.
> 
> Any suggestions ?
> 
> Niki
> 
> -- 
> Microlinux - Solutions informatiques durables
> 7, place de l'?glise - 30730 Montpezat
> Site : https://www.microlinux.fr
> Mail : info at microlinux.fr
> T?l. : 04 66 63 10 32
> Mob. : 06 51 80 12 12
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> https://lists.centos.org/mailman/listinfo/centos
> 
Salim

Le 09/02/2020 ? 14:52, Salim Shaw a ?crit :
> Very strange and as you suggested delete the ifcfg-eth0 file and recreate,
> specify your settings. I suspect your wireless device and or systemboard is
> faulty. Is there a BIOS hardware self-test you could perform to check the
> integrity of your hardware?
There is no wireless device on this PC.

Just an onboard NIC and then an additional PCI NIC.

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Hello,
Am Sonntag, 9. Februar 2020, 14:10:44 CET schrieb Nicolas
Kovacs:
> Hi,
> 
> I've done my fair share of CentOS 7 installations, but this is the
first
> time I have this kind of weird problem. Here goes.
> 
> In my office I have a battered Dell Optiplex 320 PC with two NICs that
I'm
> using as a bare metal sandbox server for testing purposes.
> 
> The CentOS 7 installer sees the connected network card as eth0. But after
> the first reboot, the interface comes up as eth1.
> 
> My first reflex was to rename ifcfg-eth0 to ifcfg-eth1 and edit it
> accordingly. Weirdly enough, on the subsequent reboot the interface comes
> back as eth0.
> 
> I took a peek in /etc/udev/rules.d to see if there was any persistent
> interface definition, but the directory is empty.
> 
> On a side note, I installed Ubuntu Server 16.04 LTS on that same machine
and
> got the exact same problem. Debian installer sees the main network
> interface as eth0, but on the first reboot the interface comes back as
> eth1.
 
> Any suggestions ?
this is coming from The NetworkManager?

I set in my config *-eth0 the HWADDR=XXXXXXXXXXXX
and NM_CONTROLLED=no


-- 
mit freundlichen Gr??en / best regards

  G?nther J. Niederwimmer

Le 09/02/2020 ? 15:15, G?nther J. Niederwimmer a ?crit?:
> this is coming from The NetworkManager?
> 
> I set in my config *-eth0 the HWADDR=XXXXXXXXXXXX
> and NM_CONTROLLED=no
I forgot to add : I removed NetworkManager as I do on all my servers.

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Le 09/02/2020 ? 14:10, Nicolas Kovacs a ?crit?:
> Any suggestions ?
I forgot to add. The onboard NIC is a Broadcom card.

$ lspci | grep -i net
02:02.0 Ethernet controller: Realtek Semiconductor Co., Ltd. 
RTL-8100/8101L/8139 PCI Fast Ethernet Adapter (rev 10)
02:09.0 Ethernet controller: Broadcom Inc. and subsidiaries BCM4401-B0 
100Base-TX (rev 02)

This card gets randomly renamed to either eth0 or eth1 after every reboot.

This is weird.

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Am 09.02.2020 um 16:14 schrieb Nicolas Kovacs:
> Le 09/02/2020 ? 14:10, Nicolas Kovacs a ?crit?:
>> Any suggestions ?
> 
> I forgot to add. The onboard NIC is a Broadcom card.
> 
> $ lspci | grep -i net
> 02:02.0 Ethernet controller: Realtek Semiconductor Co., Ltd. 
> RTL-8100/8101L/8139 PCI Fast Ethernet Adapter (rev 10)
> 02:09.0 Ethernet controller: Broadcom Inc. and subsidiaries BCM4401-B0 
> 100Base-TX (rev 02)
> 
> This card gets randomly renamed to either eth0 or eth1 after every reboot.
> 
> This is weird.

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/networking_guide/sec-Troubleshooting_Network_Device_Naming

Example 11.4

"Kernel always uses the ethX naming convention at boot when it 
enumerates network devices. Due to parallelization, the order of the 
kernel interface enumeration is expected to vary across reboots."

Alexander