[CentOS] Problem after last Update

Hello,

why it is always a Problem when a kernel, firewall or KVM update is installed ?

I have a system with a server CentOS 7 (last)  and 6 KVM Clients after the 
Update Installation and reboot the most in Network is not functional ?

I lost NIC's and the firewalld change the zone ......

I have always to control is the KVM Clients working ?

Have any a idea what is wrong on my system ?

Thanks for a answer, 
 
-- 
mit freundlichen Grüssen / best regards

  Günther J. Niederwimmer