To Enable Forwarding When Using firewalld
firewalld is an iptables controller that defines rules for persistent network traffic.
If you are using firewalld with a Red Hat Enterprise Linux (RHEL) 7.3 operating system, you must enable forwarding on the docker0 device.
You must also forward any packets being sent from or to the 10.0.0.0/8 subnet.
To Determine if You Are Using firewalld
To determine if your system is using firewall run the following command:
systemctl status firewalld.service
If firewalld is installed, this command returns the following:
$ sudo systemctl status firewalld.service
* firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
Active: inactive (dead)
Docs: man:firewalld(1)If firewalld is not installed, this command returns an error message.
Enabling Forwarding
To enable forwarding on the docker0 device, run the following commands:
firewall-cmd --permanent --direct --add-rule ipv4 filter FORWARD 1 -o docker0 -j ACCEPT -m comment --comment "docker subnet"
firewall-cmd --permanent --direct --add-rule ipv4 filter FORWARD 1 -s 10.0.0.0/8 -j ACCEPT -m comment --comment "docker subnet"To enable forwarding on the 10.0.0.0/8 subnet, run the following commands:
firewall-cmd --permanent --direct --add-rule ipv4 filter INPUT 1 -s 10.0.0.0/8 -j ACCEPT -m comment --comment "docker subnet"
firewall-cmd --permanent --direct --add-rule ipv4 filter INPUT 1 -d 10.0.0.0/8 -j ACCEPT -m comment --comment "docker subnet"