firewalld.conf is loaded by firewalld during the initialization process. The file contains the basic configuration options for firewalld.
These are the options that can be set in the config file:
This sets the default zone for connections or interfaces if the zone is not selected or specified by NetworkManager, initscripts or command line tool. The default zone is public.
Deprecated. This option is ignored and no longer used. Marks are no longer used internally.
If firewalld stops, it cleans up all firewall rules. Setting this option to no or false leaves the current firewall rules untouched. The default value is yes or true.
If this option is enabled, firewall changes with the D-Bus interface will be limited to applications that are listed in the lockdown whitelist (see firewalld.lockdown-whitelist(5)). The default value is no or false.
If this option is enabled (it is by default), reverse path filter test on a packet for IPv6 is performed. If a reply to the packet would be sent via the same interface that the packet arrived on, the packet will match and be accepted, otherwise dropped. For IPv4 the rp_filter is controlled using sysctl.
If this option is disabled (it is by default), combined -restore calls are used and not individual calls to apply changes to the firewall. The use of individiual calls increases the time that is needed to apply changes and to start the daemon, but is good for debugging as error messages are more specific.
Add logging rules right before reject and drop rules in the INPUT, FORWARD and OUTPUT chains for the default rules and also final reject and drop rules in zones for the configured link-layer packet type. The possible values are: all, unicast, broadcast, multicast and off. The default setting is off, which disables the logging.
Deprecated. This option is ignored and no longer used.
Selects the firewall backend implementation. Possible values are; nftables (default), or iptables. This applies to all firewalld primitives. The only exception is direct and passthrough rules which always use the traditional iptables, ip6tables, and ebtables backends.
Flush all runtime rules on a reload. In previous releases some runtime configuration was retained during a reload, namely; interface to zone assignment, and direct rules. This was confusing to users. To get the old behavior set this to "no". Defaults to "yes".
As per RFC 3964, filter IPv6 traffic with 6to4 destination addresses that correspond to IPv4 addresses that should not be routed over the public internet. Defaults to "yes".
Older versions of firewalld had undocumented behavior known as "zone drifting". This allowed packets to ingress multiple zones - this is a violation of zone based firewalls. However, some users rely on this behavior to have a "catch-all" zone, e.g. the default zone. You can enable this if you desire such behavior. It's disabled by default for security reasons. Note: If "yes" packets will only drift from source based zones to interface based zones (including the default zone). Packets never drift from interface based zones to other interfaces based zones (including the default zone). Valid values; "yes", "no". Defaults to "no".
firewall-applet(1), firewalld(1), firewall-cmd(1), firewall-config(1), firewalld.conf(5), firewalld.direct(5), firewalld.dbus(5), firewalld.icmptype(5), firewalld.lockdown-whitelist(5), firewall-offline-cmd(1), firewalld.richlanguage(5), firewalld.service(5), firewalld.zone(5), firewalld.zones(5), firewalld.policy(5), firewalld.policies(5), firewalld.ipset(5), firewalld.helper(5)
firewalld home page:
More documentation with examples:
Thomas Woerner <email@example.com>
Jiri Popelka <firstname.lastname@example.org>
Eric Garver <email@example.com>
firewall-applet(1), firewall-cmd(1), firewall-config(1), firewalld(1), firewalld.dbus(5), firewalld.direct(5), firewalld.helper(5), firewalld.icmptype(5), firewalld.ipset(5), firewalld.lockdown-whitelist(5), firewalld.policies(5), firewalld.policy(5), firewalld.richlanguage(5), firewalld.service(5), firewalld.zone(5), firewalld.zones(5), firewall-offline-cmd(1).