hello Greg, thanks for the answer, now I am not so alone ;-) this Problem with the third NIC in a KVM Client is from Update to Update stronger. I mean on start the Installation "CentOS 7.0" we don't have this Problem! without NetworkManager is run, on my system, I can't start the third Network- Card, I have always a LSB Error on the KVM-Clients ?? So now I found a workaround for my Problem :-(. (What are changed in the Network Configuration) I set up the first and second NIC to "hostdev" (hardware) this is running also before the update and set “NM_CONTROLLED=no” to this NIC's. The third is a Bridge controlled Interface now is running with NetworkManager as a static Interface with "PEERDNS=no" so I have my resolv.conf is not always change and NetworkManager don't create a new Interface with a DHCP config ?? Why Network Manager do that with 7.6, I can't say but I am not happy witzh this update :-(. Am Samstag, 15. Dezember 2018, 18:27:39 CET schrieb Gregory P. Ennis: > I have two units that are different users with desktop KVM hypervisors > Centos 7 hosts. One had only one network card and it went through the > migration from 7.5 to 7.6 without a problem. The other had three network > cards and it became disabled with failed network connections. I had to > rebuild the network and did so in the following manner. > > #1. NetworkManager had been turned off. I turned NetworkManger from off to > on so that it would create appropriate ifcfg-* files for three network > cards after a reboot. > > #2. I modified the appropriate ifcf-* files and created a new network > bridge with one of the cards. After the update to 7.6 I was able to leave > NetworkManager running as long as I had the appropriate ifcf-* file and the > bridge set with “NM_CONTROLLED=no”. With Centos 7.5 I had to disable > NetworkManager because it kept destroying the bridge even with the switch > “NM_CONTROLLED=no”. > > #3. Lastly I had to change the references to the new bridge in the KVM > guests. > > After this everything has worked like it did before the upgrade. My take on > this is that kvm hypervisors that are set up with more than one nic card > have the potential of having their network setup corrupted when the > migration from 7.5 to 7.6 occurs. On a positive note NetworkManager now > works with a network bridge with 7.6, but it did not work for me with 7.5. > > Good Luck!!! > > Greg -- mit freundliche Grüßen / best regards, Günther J. Niederwimmer _______________________________________________ CentOS mailing list CentOS@xxxxxxxxxx https://lists.centos.org/mailman/listinfo/centos