I have two installations of SLES11 SP2 on X86-64 that I use to host KVM VMs. They are configured for bridging networking and it all works after I use sysctl to set
net.bridge.bridge-nf-call-ip6tables = 0
net.bridge.bridge-nf-call-iptables = 0
net.bridge.bridge-nf-call-arptables = 0
I have added these three lines to the end of /etc/sysctl.conf, expecting that the system will set them on boot. This does not happen. /etc/sysctl.conf is being loaded at boot as I can see other values from that file change when I change them. Because of this I can not load VMs at boot with any reliability. If I change these settings and then load the VMs everything works fine. Why is SLES not setting these values?