nesting — shorewall6 Nested Zones




In shorewall6-zones(5), a zone may be declared to be a sub-zone of one or more other zones using the above syntax.

Where zones are nested, the CONTINUE policy in shorewall6-policy(5) allows hosts that are within multiple zones to be managed under the rules of all of these zones.



        #ZONE    TYPE        OPTION
        fw       firewall
        net      ipv6
        sam:net  ipv6
        loc      ipv6


        -         eth0          detect        blacklist
        loc       eth1          detect


        #ZONE     HOST(S)                     OPTIONS
        net       eth0:[::\]
        sam       eth0:[2001:19f0:feee::dead:beef:cafe]


        #SOURCE      DEST        POLICY       LOG LEVEL
        loc          net         ACCEPT
        sam          all         CONTINUE
        net          all         DROP         info
        all          all         REJECT       info

The second entry above says that when Sam is the client, connection requests should first be processed under rules where the source zone is sam and if there is no match then the connection request should be treated under rules where the source zone is net. It is important that this policy be listed BEFORE the next policy (net to all). You can have this policy generated for you automatically by using the IMPLICIT_CONTINUE option in shorewall6.conf(5).

Partial /etc/shorewall6/rules:

        #ACTION   SOURCE    DEST                  PROTO    DEST PORT(S)
        ACCEPT    sam       loc:2001:19f0:feee::3 tcp      ssh
        ACCEPT    net       loc:2001:19f0:feee::5 tcp      www

Given these two rules, Sam can connect with ssh to 2001:19f0:feee::3. Like all hosts in the net zone, Sam can connect to TCP port 80 on 2001:19f0:feee::5. The order of the rules is not significant.








shorewall6(8), shorewall6-accounting(5), shorewall6-actions(5), shorewall6-blacklist(5), shorewall6-hosts(5), shorewall6-interfaces(5), shorewall6-maclist(5), shorewall6-params(5), shorewall6-policy(5), shorewall6-providers(5), shorewall6-route_rules(5), shorewall6-routestopped(5), shorewall6-rules(5), shorewall6.conf(5), shorewall6-tcclasses(5), shorewall6-tcdevices(5), shorewall6-tcrules(5), shorewall6-tos(5), shorewall6-tunnels(5), shorewall6-zones(5)