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 7 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.