Hello, I got it working, but I'm not sure if it is right. I'm starting to have Problems again.
Configured on the Host Server with Yast2:
eth1 is connected to Switch and has IP: 192.168.111.189/24 Gateway 192.168.111.100 "HOSTNAME"
eth0 is connected to Switch and has IP: 0.0.0.0/24 (here I also found should be set to 0.0.0.0/32, that I did on another 2 Host Servers. Both ways seem to work.)
vlan1 set eth0, IP:0.0.0.0/32 "NO HOSTNAME" (acoording to my Network Section for Netz 192.168.1.0)
vlan23 set eth0, IP:0.0.0.0/32 "NO HOSTNAME" (acoording to my Network Section for Netz 192.168.23.0)
br1 set to vlan1, IP:0.0.0.0/32 "NO HOSTNAME" (acoording to my Network Section for Netz 192.168.1.0)
br23 set to vlan1, IP:0.0.0.0/32 "NO HOSTNAME" (acoording to my Network Section for Netz 192.168.23.0)

Are these settings OK?

I have 3 Host Servers, each with 3 to 6 VM Servers installed. They seemed to work fine, untill I wanted to install another Host Server. As soon as it booted, I got on all Host Servers,
br23: received packet on vlan23 woth own address as source address
br23: received packet on vlan23 woth own address as source address
br1: received packet on vlan1 woth own address as source address
br1: received packet on vlan1 woth own address as source address
The above message the Servers got ever 2 minutes untill I shut the Server down. So I completly reinstalled it and got the same Thing. I have googled now for 2 days and have not found any solution.
Do you have Ideas?

The guest Servers are connected with br1 or br23 using vnet? and virtio Network from KVM.