[CentOS] Upgrade from 7.6.1810 to 7.7.1908 -> Interfaces order not static

Thu Oct 3 07:17:44 UTC 2019
Jobst Schmalenbach <jobst at barrett.com.au>

Hi

For years (long time) I had " net.ifnames=0 biosdevname=0 " and it worked as it should (6.X, 7.X)

I never had any problems, until yesterday.

I started upgrading my machines and I stopped after the first one showed 
issues and I will not update all the other ones until this is sorted.

I have problems keeping the interfaces in order as I wanted them to be assigned 
to eth0, eth1 .. eth4

Every reboot the order of eth1, eth2 and eth3 change BUT eth0 stays.

Now when I read this 

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

then I am doing the correct thing by adding the MAC as in so:

  DEVICE=eth0
  IPADDR=...
  ...
  GATEWAY=...
  ONBOOT=yes
  BOOTPROTO=none
  USERCTL=no
  NOZEROCONF=true
  TYPE=Ethernet
  NM_CONTROLLED=no
  HWADDR=01:23:45:67:78:9a

This works for eth0 but all the other ones the kernel complains

  /etc/sysconfig/network-scripts/ifup-eth: Device eth[1,2,3] has different MAC address than expected, ignoring

NOTE: this worked until yesterday, I could reboot, update whatever
it always came up in the same way and I also did not need to swap the 
network cables EVERY time ... Even without HWADDR/MAX adddress I
have to swap the cables every time (eth[1,2,3]).

Did something change in the kernel/networking/udev I am not aware of?
What am I doing wrong all over sudden?


Jobst



-- 
Jobst Schmalenbach
Programmer - an organism that turns coffee into software !