Provided by: firewalld_2.1.1-1_all 
NAME
firewalld.policies - firewalld policies
DESCRIPTION
What is a policy?
A policy applies a set of rules to traffic flowing between between zones (see zones (see
firewalld.zones(5)). The policy affects traffic in a stateful unidirectional manner, e.g.
zoneA to zoneB. This allows asynchronous filtering policies.
A policy's relationship to zones is defined by assigning a set of ingress zones and a set
of egress zones. For example, if the set of ingress zones contains "public" and the set of
egress zones contains "internal" then the policy will affect all traffic flowing from the
"public" zone to the "internal" zone. However, since policies are unidirectional it will
not apply to traffic flowing from "internal" to "public". Note that the ingress set and
egress set can contain multiple zones.
Active Policies
Policies only become active if all of the following are true.
• The ingress zones list contain at least one regular zone or a single symbolic zone.
• The egress zones list contain at least one regular zone or a single symbolic zone.
• For non symbolic zones, the zone must be active. That is, it must have interfaces or
sources assigned to it.
If the policy is not active then the policy has no effect.
Symbolic Zones
Regular zones are not enough to express every form of packet filtering. For example there
is no zone to represent traffic flowing to or from the host running firewalld. As such,
there are some symbolic zones to fill these gaps. However, symbolic zones are unique in
that they're the only zone allowed in the ingress or egress zone sets. For example, you
cannot use "public" and "HOST" in the ingress zones.
Symbolic zones:
1. HOST
This symbolic zone is for traffic flowing to or from the host running firewalld. This
corresponds to netfilter (iptables/nftables) chains INPUT and OUTPUT.
• If used in the egress zones list it will apply to traffic on the INPUT chain.
• If used in the ingress zones list it will apply to traffic on the OUTPUT chain.
2. ANY
This symbolic zone behaves like a wildcard for the ingress and egress zones. With the
exception that it does not include "HOST". It's useful if you want a policy to apply
to every zone.
• If used in the ingress zones list it will apply for traffic originating from any
zone.
• If used in the egress zones list it will apply for traffic destined to any zone.
Predefined Policies
firewalld ships with some predefined policies. These may or may not be active by default.
For details see the description of each policy.
• allow-host-ipv6
Similarity to Zones
Policies are similar to zones in that they are an attachment point for firewalld's
primitives: services, ports, forward ports, etc. This is not a coincidence. Policies are a
generalization of how zones have traditionally achieved filtering. In fact, in modern
firewalld zones are internally implemented as a set of policies.
The main difference between policies and zones is that policies allow filtering in all
directions: input, output, and forwarding. With a couple of exceptions zones only allow
input filtering which is sufficient for an end station firewalling. However, for network
level filtering or filtering on behalf of virtual machines and containers something more
flexible, i.e. policies, are needed.
SEE ALSO
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)
NOTES
firewalld home page:
http://firewalld.org
AUTHORS
Thomas Woerner <twoerner@redhat.com>
Developer
Jiri Popelka <jpopelka@redhat.com>
Developer
Eric Garver <eric@garver.life>
Developer