[CentOS] After upgrade to CentOS 8.1 default gateway missing

Thu Jan 16 12:57:57 UTC 2020
Asle Ommundsen <aommundsen at gmail.com>


Tonight I upgraded two CentOS 8 boxes to CentOS 8.1 (1911). Then after a  
reboot of the first server the network was unavailable. In IPMI console  
everything except the network was looking good. Network was unreachable.  
No errors in NetworkManager. I also restarted NetworkManager, but it did  
not help. Then I discovered that the default gateway suddenly was missing.

Then I rebooted the server one more time, but network was still down.

Then both myself and a technician in my datcenter was debugging this (I  
had to wake him up in the middle of the night, costing me a lot of money),  
without finding any reason for why the default gateway was missing after  

Then we rebooted the server a third time, and all of a sudden the problem  
was gone and the default gateway was back.

Then, after this, I also upgraded my second CentOS 8 server to CentOS 8.1  
and did a reboot. And the very same thing happened to this server after  
reboot! The default gateway was missing after reboot, and network was  
down. Then I did a extra reboot of this server also, and when it came back  
up everything was working correct and the default gateway was back.

So the first server I needed to reboot two extra times to have the default  
gateway back and network working. And the second server I needed to reboot  
only one extra time for the problem to be solved.

The two boxes is not VPSs or anything, but bare metal dedicated servers.

Also prior to upgrading to CentOS 8.1, these two boxes has been rebooted  
serveral times previously, without any problems at all. Only after  
upgrading to CentOS 8.1 this happened on both of them for the first time.

I can't believe I am the only one that experience this? My guess is that  
this is a unknown random intermittent bug in CentOS 8.1 that kicked in. I  
just hope this does not continue to happen in the future. If you  
experienced the same, please share it with a reply. Thank you!

Kind regards,
Asle Ommundsen