[CentOS] C7 and firewalld and ethernet bridge

Fri Jan 18 23:09:17 UTC 2019
Gordon Messmer <gordon.messmer at gmail.com>

On 1/18/19 10:34 AM, mark wrote:
> Does someone have a link to a how-to-do-it with firewalld, not "disable
> firewalld and use iptables"?

Are you trying to filter the packets crossing the bridge device?

If so, you should need three files:

 1. /etc/dracut.conf.d/br_netfilter.conf:
    add_drivers+=" br_netfilter"
 2. /etc/modprobe.d/br_netfilter.conf:
    softdep bridge post: br_netfilter
 3. /etc/sysctl.d/90-br_netfilter.conf:
    # Enable netfilter on bridges.
    net.bridge.bridge-nf-call-ip6tables = 1
    net.bridge.bridge-nf-call-iptables = 1
    net.bridge.bridge-nf-call-arptables = 1

You'll want to rebuild your initrd so that br_netfilter is included and 
loaded at boot.  From there, filtering the bridge is the same as 
filtering FORWARD rules, generally (IIRC).