NM controlled bridge turns on netfilter

[Mateusz Marzantowicz]

On 23.10.2013 10:44, Paul Knox-Kennedy wrote:
> I have a host recently updated to f20, with virtual machines using
> bridged networking. When I switch to NetworkManager controlled
> networking, the virtual machines' DHCP requests failed.
>  
> After much messing around, I have found that when NM is on, by the time
> the system has booted, bridge-nf-call-iptables,
> bridge-nf-call-ip6-tables and bridge-nf-call-arptables have all been set
> to 1, so something has overriden the setting from
> /usr/lib/sysctl.d/00-system.conf.
>  
> Is there some setting I am missing here?
>  

You're not missing anything. It is a BUG not resolved to this day. There
is a workaround that works perfectly for me and maybe others. Create
file /etc/NetworkManager/dispatcher.d/00-sysctl with following content:

#!/bin/sh

/usr/lib/systemd/systemd-sysctl

exit 0


Mateusz Marzantowicz