firewalld.conf - firewalld configuration file
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.
For some firewall settings several rules are
needed in different tables to be able to handle packets in the correct way. To
achieve that these packets are marked using the MARK target iptables(8)
and ip6tables(8). With the MinimalMark option a block of marks can be
reserved for private use; only marks over this value are used. The default
MinimalMark value is 100.
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.
For the secure use of iptables and connection
tracking helpers it is recommended to turn AutomaticHelpers off. But this
might have side effects on other services using the netfilter helpers as the
sysctl setting in /proc/sys/net/netfilter/nf_conntrack_helper will be changed.
With the system setting, the default value set in the kernel or with sysctl
will be used. Possible values are: yes, no and system.
The default setting is system.
firewalld home page:
More documentation with examples: