Zone Policy

In zone-based policy, interfaces are assigned to zones, and inspection policy is applied to traffic moving between the zones and acted on according to firewall rules. A Zone is a group of interfaces that have similar functions or features. It establishes the security borders of a network. A zone defines a boundary where traffic is subjected to policy restrictions as it crosses to another region of a network.

Key Points:

A zone must be configured before an interface is assigned to it and an interface can be assigned to only a single zone.
All traffic to and from an interface within a zone is permitted.
All traffic between zones is affected by existing policies
Traffic cannot flow between zone member interface and any interface that is not a zone member.
You need 2 separate firewalls to define traffic: one for each direction.

Example: LAN Network is given SSH access to VyOS box.

Firewall rules:

set firewall name lan-local default-action 'drop'
set firewall name lan-local rule 1 action 'accept'
set firewall name lan-local rule 1 state established 'enable'
set firewall name lan-local rule 1 state related 'enable'
set firewall name lan-local rule 2 action 'drop'
set firewall name lan-local rule 2 state invalid 'enable'
set firewall name lan-local rule 2 log enable
set firewall name lan-local rule 100 action 'accept'
set firewall name lan-local rule 100 destination port '22'
set firewall name lan-local rule 100 log 'enable'
set firewall name lan-local rule 100 protocol 'tcp'
set firewall name local-lan default-action 'drop'
set firewall name local-lan rule 1 action 'accept'
set firewall name local-lan rule 1 state established 'enable'
set firewall name local-lan rule 1 state related 'enable'
set firewall name local-lan rule 2 action 'drop'
set firewall name local-lan rule 2 state invalid 'enable'
set firewall name local-lan rule 2 log enable
set firewall name local-lan rule 100 action 'accept'
set firewall name local-lan rule 100 destination address '192.168.0.0/24'
set firewall name local-lan rule 100 log 'enable'
set firewall name local-lan rule 100 protocol 'tcp'

Zone-policy Config:

set zone-policy zone lan default-action 'drop'
set zone-policy zone lan description 'Local Area Network'
set zone-policy zone lan interface 'eth2'
set zone-policy zone lan from local firewall name 'lan-local'
set zone-policy zone local default-action 'drop'
set zone-policy zone local description 'system-defined zone'
set zone-policy zone local from lan firewall name 'local-lan'
set zone-policy zone local local-zone

A detailed zone-based policy example is written in the Configuration-Blueprints section.