Firewalld

External

• Red Hat Enterprise Linux 7 Security Guide firewalld: https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Security_Guide/sec-Using_Firewalls.html#sec-Introduction_to_firewalld

Internal

• Linux Security
• iptables Concepts

Overview

firewalld is a firewall service daemon with D-BUS interface. It is used to implement a dynamic firewall. The firewall supports network/firewall zones to define the trust level of network connections or interfaces. It has support for IPv4, IPv6 and for ethernet bridges and has a separation of runtime and permanent configuration options. It also supports an interface for services or applications to add firewall rules directly.

firewalld comes with a graphical configuration tool firewall-config. firewalld uses the iptables tool to communicate with netfilter in the kernel.

The iptables service and firewalld are incompatible, you must use one or another.

Operations

Check the Status

systemctl status firewalld

Running firewalld:

● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
   Active: active (running) since Tue 2016-01-05 08:34:44 PST; 2h 26min ago
 Main PID: 782 (firewalld)
   CGroup: /system.slice/firewalld.service
           └─782 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid

Jan 05 08:34:44 now510.local systemd[1]: Starting firewalld - dynamic firewall daemon...
Jan 05 08:34:44 now510.local systemd[1]: Started firewalld - dynamic firewall daemon.

Stopped firewalld:

● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)

Disable

This is how firewalld is prevented to start at boot:

systemctl stop firewalld
systemctl disable firewalld

If you are sure that you won't use firewalld in the future, you can remove it completely:

yum -y remove firewalld