Comment # 26 on bug 1158817 from Giacomo Comes

(In reply to Martin Wilck from comment #21)
> (In reply to Giacomo Comes from comment #19)
> 
> > I don't think firewalld has anything to do with the problem here.
> > If I add again in /etc/modprobe.d/00-system.conf:
> >   softdep bridge post: br_netfilter
> > and I disable firewalld the network in KVM still does not work.
> 
> What exactly have you done to disable firewalld? "systemctl stop firewalld"?
> What does "iptables-save" output after that?

I run "systemctl disable firewalld" and then reboot.
The output of "iptables-save" is then empty.

> > If the problem was due to a strange firewall rule, disabling firewalld
> > should make the issue go away, isn't it?
> 
> Yes. But without any firewall rules, disabling br_netfilter wouldn't have
> any effect, either. The only purpose of br_netfilter is to call netfilter
> rules for bridged packets, and that would have no effect if there were no
> rules.

Apparently that's not the case. Without any firewall rules it makes a
difference if br_netfilter is enabled or not. At least for this bug.

> > Also I have the suspect that libvirt has nothing to do with the problem as
> > well.
> > And the reason is that I start qemu-kvm manually (from a script actually)
> > and libvirt is not used at all.
> 
> But you're using a bridge, right?

Yes I use a bridge.