:lastproofread: 2024-07-03 .. _firewall-configuration: ############################# Bridge Firewall Configuration ############################# ******** Overview ******** In this section there's useful information on all firewall configuration that can be done regarding bridges, and appropriate op-mode commands. Configuration commands covered in this section: .. cfgcmd:: set firewall bridge ... From the main structure defined in :doc:`Firewall Overview` in this section you can find detailed information only for the next part of the general structure: .. code-block:: none - set firewall * bridge - forward + filter - input + filter - output + filter - prerouting + filter - name + custom_name Traffic which is received by the router on an interface which is member of a bridge is processed on the **Bridge Layer**. Before the bridge decision is made, all packets are analyzed at **Prerouting**. First filters can be applied here, and also rules for ignoring connection tracking system can be configured. The relevant configuration that acts in **prerouting** is: * ``set firewall bridge prerouting filter ...``. For traffic that needs to be switched internally by the bridge, base chain is **forward**, and it's base command for filtering is ``set firewall bridge forward filter ...``, which happens in stage 4, highlighted with red color. .. figure:: /_static/images/firewall-bridge-forward.png For traffic destined to the router itself, or that needs to be routed (assuming a layer3 bridge is configured), the base chain is **input**, the base command is ``set firewall bridge input filter ...`` and the path is: .. figure:: /_static/images/firewall-bridge-input.png If it's not dropped, then the packet is sent to **IP Layer**, and will be processed by the **IP Layer** firewall: IPv4 or IPv6 ruleset. Check once again the :doc:`general packet flow diagram` if needed. And for traffic that originates from the bridge itself, the base chain is **output**, base command is ``set firewall bridge output filter ...``, and the path is: .. figure:: /_static/images/firewall-bridge-output.png Custom bridge firewall chains can be created with the command ``set firewall bridge name ...``. In order to use such custom chain, a rule with action jump, and the appropriate target should be defined in a base chain. ************ Bridge Rules ************ For firewall filtering, firewall rules need to be created. Each rule is numbered, has an action to apply if the rule is matched, and the ability to specify multiple matching criteria. Data packets go through the rules from 1 - 999999, so order is crucial. At the first match the action of the rule will be executed. Actions ======= If a rule is defined, then an action must be defined for it. This tells the firewall what to do if all matching criterea in the rule are met. In firewall bridge rules, the action can be: * ``accept``: accept the packet. * ``continue``: continue parsing next rule. * ``drop``: drop the packet. * ``jump``: jump to another custom chain. * ``return``: Return from the current chain and continue at the next rule of the last chain. * ``queue``: Enqueue packet to userspace. * ``notrack``: ignore connection tracking system. This action is only available in prerouting chain. .. cfgcmd:: set firewall bridge forward filter rule <1-999999> action [accept | continue | drop | jump | queue | return] .. cfgcmd:: set firewall bridge input filter rule <1-999999> action [accept | continue | drop | jump | queue | return] .. cfgcmd:: set firewall bridge output filter rule <1-999999> action [accept | continue | drop | jump | queue | return] .. cfgcmd:: set firewall bridge prerouting filter rule <1-999999> action [accept | continue | drop | jump | notrack | queue | return] .. cfgcmd:: set firewall bridge name rule <1-999999> action [accept | continue | drop | jump | queue | return] This required setting defines the action of the current rule. If action is set to jump, then jump-target is also needed. .. cfgcmd:: set firewall bridge forward filter rule <1-999999> jump-target .. cfgcmd:: set firewall bridge input filter rule <1-999999> jump-target .. cfgcmd:: set firewall bridge output filter rule <1-999999> jump-target .. cfgcmd:: set firewall bridge prerouting filter rule <1-999999> jump-target .. cfgcmd:: set firewall bridge name rule <1-999999> jump-target If action is set to ``queue``, use next command to specify the queue target. Range is also supported: .. cfgcmd:: set firewall bridge forward filter rule <1-999999> queue <0-65535> .. cfgcmd:: set firewall bridge input filter rule <1-999999> queue <0-65535> .. cfgcmd:: set firewall bridge output filter rule <1-999999> queue <0-65535> .. cfgcmd:: set firewall bridge prerouting filter rule <1-999999> queue <0-65535> .. cfgcmd:: set firewall bridge name rule <1-999999> queue <0-65535> Also, if action is set to ``queue``, use next command to specify the queue options. Possible options are ``bypass`` and ``fanout``: .. cfgcmd:: set firewall bridge forward filter rule <1-999999> queue-options bypass .. cfgcmd:: set firewall bridge input filter rule <1-999999> queue-options bypass .. cfgcmd:: set firewall bridge output filter rule <1-999999> queue-options bypass .. cfgcmd:: set firewall bridge prerouting filter rule <1-999999> queue-options bypass .. cfgcmd:: set firewall bridge name rule <1-999999> queue-options bypass .. cfgcmd:: set firewall bridge forward filter rule <1-999999> queue-options fanout .. cfgcmd:: set firewall bridge input filter rule <1-999999> queue-options fanout .. cfgcmd:: set firewall bridge output filter rule <1-999999> queue-options fanout .. cfgcmd:: set firewall bridge prerouting filter rule <1-999999> queue-options fanout .. cfgcmd:: set firewall bridge name rule <1-999999> queue-options fanout Also, **default-action** is an action that takes place whenever a packet does not match any rule in its' chain. For base chains, possible options for **default-action** are **accept** or **drop**. .. cfgcmd:: set firewall bridge forward filter default-action [accept | drop] .. cfgcmd:: set firewall bridge input filter default-action [accept | drop] .. cfgcmd:: set firewall bridge output filter default-action [accept | drop] .. cfgcmd:: set firewall bridge prerouting filter default-action [accept | drop] .. cfgcmd:: set firewall bridge name default-action [accept | continue | drop | jump | reject | return] This sets the default action of the rule-set if a packet does not match any of the rules in that chain. If default-action is set to ``jump``, then ``default-jump-target`` is also needed. Note that for base chains, default action can only be set to ``accept`` or ``drop``, while on custom chains more actions are available. .. cfgcmd:: set firewall bridge name default-jump-target To be used only when ``default-action`` is set to ``jump``. Use this command to specify jump target for default rule. .. note:: **Important note about default-actions:** If the default action for any base chain is not defined, then the default action is set to **accept** for that chain. For custom chains, if the default action is not defined, then the default-action is set to **drop**. Firewall Logs ============= Logging can be enable for every single firewall rule. If enabled, other log options can be defined. .. cfgcmd:: set firewall bridge forward filter rule <1-999999> log .. cfgcmd:: set firewall bridge input filter rule <1-999999> log .. cfgcmd:: set firewall bridge output filter rule <1-999999> log .. cfgcmd:: set firewall bridge prerouting filter rule <1-999999> log .. cfgcmd:: set firewall bridge name rule <1-999999> log Enable logging for the matched packet. If this configuration command is not present, then the log is not enabled. .. cfgcmd:: set firewall bridge forward filter default-log .. cfgcmd:: set firewall bridge input filter default-log .. cfgcmd:: set firewall bridge output filter default-log .. cfgcmd:: set firewall bridge prerouting filter default-log .. cfgcmd:: set firewall bridge name default-log Use this command to enable the logging of the default action on the specified chain. .. cfgcmd:: set firewall bridge forward filter rule <1-999999> log-options level [emerg | alert | crit | err | warn | notice | info | debug] .. cfgcmd:: set firewall bridge input filter rule <1-999999> log-options level [emerg | alert | crit | err | warn | notice | info | debug] .. cfgcmd:: set firewall bridge output filter rule <1-999999> log-options level [emerg | alert | crit | err | warn | notice | info | debug] .. cfgcmd:: set firewall bridge prerouting filter rule <1-999999> log-options level [emerg | alert | crit | err | warn | notice | info | debug] .. cfgcmd:: set firewall bridge name rule <1-999999> log-options level [emerg | alert | crit | err | warn | notice | info | debug] Define log-level. Only applicable if rule log is enabled. .. cfgcmd:: set firewall bridge forward filter rule <1-999999> log-options group <0-65535> .. cfgcmd:: set firewall bridge input filter rule <1-999999> log-options group <0-65535> .. cfgcmd:: set firewall bridge output filter rule <1-999999> log-options group <0-65535> .. cfgcmd:: set firewall bridge prerouting filter rule <1-999999> log-options group <0-65535> .. cfgcmd:: set firewall bridge name rule <1-999999> log-options group <0-65535> Define the log group to send messages to. Only applicable if rule log is enabled. .. cfgcmd:: set firewall bridge forward filter rule <1-999999> log-options snapshot-length <0-9000> .. cfgcmd:: set firewall bridge input filter rule <1-999999> log-options snapshot-length <0-9000> .. cfgcmd:: set firewall bridge output filter rule <1-999999> log-options snapshot-length <0-9000> .. cfgcmd:: set firewall bridge prerouting filter rule <1-999999> log-options snapshot-length <0-9000> .. cfgcmd:: set firewall bridge name rule <1-999999> log-options snapshot-length <0-9000> Define length of packet payload to include in netlink message. Only applicable if rule log is enabled and the log group is defined. .. cfgcmd:: set firewall bridge forward filter rule <1-999999> log-options queue-threshold <0-65535> .. cfgcmd:: set firewall bridge input filter rule <1-999999> log-options queue-threshold <0-65535> .. cfgcmd:: set firewall bridge output filter rule <1-999999> log-options queue-threshold <0-65535> .. cfgcmd:: set firewall bridge prerouting filter rule <1-999999> log-options queue-threshold <0-65535> .. cfgcmd:: set firewall bridge name rule <1-999999> log-options queue-threshold <0-65535> Define the number of packets to queue inside the kernel before sending them to userspace. Only applicable if rule log is enabled and the log group is defined. Firewall Description ==================== For reference, a description can be defined for every defined custom chain. .. cfgcmd:: set firewall bridge name description Provide a rule-set description to a custom firewall chain. .. cfgcmd:: set firewall bridge forward filter rule <1-999999> description .. cfgcmd:: set firewall bridge input filter rule <1-999999> description .. cfgcmd:: set firewall bridge output filter rule <1-999999> description .. cfgcmd:: set firewall bridge prerouting filter rule <1-999999> description .. cfgcmd:: set firewall bridge name rule <1-999999> description Provide a description for each rule. Rule Status =========== When defining a rule, it is enabled by default. In some cases, it is useful to just disable the rule, rather than removing it. .. cfgcmd:: set firewall bridge forward filter rule <1-999999> disable .. cfgcmd:: set firewall bridge input filter rule <1-999999> disable .. cfgcmd:: set firewall bridge output filter rule <1-999999> disable .. cfgcmd:: set firewall bridge prerouting filter rule <1-999999> disable .. cfgcmd:: set firewall bridge name rule <1-999999> disable Command for disabling a rule but keep it in the configuration. Matching criteria ================= There are a lot of matching criteria against which the packet can be tested. Please refer to :doc:`IPv4` and :doc:`IPv6` matching criteria for more details. Since bridges operates at layer 2, both matchers for IPv4 and IPv6 are supported in bridge firewall configuration. Same applies for firewall groups. Use IP firewall =============== By default, for switched traffic, only the rules defined under ``set firewall bridge`` are applied. There are two global-options that can be configured in order to force deeper analysis of the packet on the IP layer. These options are: .. cfgcmd:: set firewall global-options apply-to-bridged-traffic ipv4 This command enables the IPv4 firewall for bridged traffic. If this options is used, then packet will also be parsed by rules defined in ``set firewall ipv4 ...`` .. cfgcmd:: set firewall global-options apply-to-bridged-traffic ipv6 This command enables the IPv6 firewall for bridged traffic. If this options is used, then packet will also be parsed by rules defined in ``set firewall ipv6 ...`` *********************** Operation-mode Firewall *********************** Rule-set overview ================= In this section you can find all useful firewall op-mode commands. General commands for firewall configuration, counter and statistics: .. opcmd:: show firewall .. opcmd:: show firewall summary .. opcmd:: show firewall statistics And, to print only bridge firewall information: .. opcmd:: show firewall bridge .. opcmd:: show firewall bridge forward filter .. opcmd:: show firewall bridge forward filter rule .. opcmd:: show firewall bridge name .. opcmd:: show firewall bridge name rule Show Firewall log ================= .. opcmd:: show log firewall .. opcmd:: show log firewall bridge .. opcmd:: show log firewall bridge forward .. opcmd:: show log firewall bridge forward filter .. opcmd:: show log firewall bridge name .. opcmd:: show log firewall bridge forward filter rule .. opcmd:: show log firewall bridge name rule Show the logs of all firewall; show all bridge firewall logs; show all logs for forward hook; show all logs for forward hook and priority filter; show all logs for particular custom chain; show logs for specific Rule-Set. Example ======= Configuration example: .. code-block:: none set firewall bridge forward filter default-action 'drop' set firewall bridge forward filter default-log set firewall bridge forward filter rule 10 action 'continue' set firewall bridge forward filter rule 10 inbound-interface name 'eth2' set firewall bridge forward filter rule 10 vlan id '22' set firewall bridge forward filter rule 20 action 'drop' set firewall bridge forward filter rule 20 inbound-interface group 'TRUNK-RIGHT' set firewall bridge forward filter rule 20 vlan id '60' set firewall bridge forward filter rule 30 action 'jump' set firewall bridge forward filter rule 30 jump-target 'TEST' set firewall bridge forward filter rule 30 outbound-interface name '!eth1' set firewall bridge forward filter rule 35 action 'accept' set firewall bridge forward filter rule 35 vlan id '11' set firewall bridge forward filter rule 40 action 'continue' set firewall bridge forward filter rule 40 destination mac-address '66:55:44:33:22:11' set firewall bridge forward filter rule 40 source mac-address '11:22:33:44:55:66' set firewall bridge name TEST default-action 'accept' set firewall bridge name TEST default-log set firewall bridge name TEST rule 10 action 'continue' set firewall bridge name TEST rule 10 log set firewall bridge name TEST rule 10 vlan priority '0' And op-mode commands: .. code-block:: none vyos@BRI:~$ show firewall bridge Rulesets bridge Information --------------------------------- bridge Firewall "forward filter" Rule Action Protocol Packets Bytes Conditions ------- -------- ---------- --------- ------- --------------------------------------------------------------------- 10 continue all 0 0 iifname "eth2" vlan id 22 continue 20 drop all 0 0 iifname @I_TRUNK-RIGHT vlan id 60 30 jump all 2130 170688 oifname != "eth1" jump NAME_TEST 35 accept all 2080 168616 vlan id 11 accept 40 continue all 0 0 ether daddr 66:55:44:33:22:11 ether saddr 11:22:33:44:55:66 continue default drop all 0 0 --------------------------------- bridge Firewall "name TEST" Rule Action Protocol Packets Bytes Conditions ------- -------- ---------- --------- ------- -------------------------------------------------- 10 continue all 2130 170688 vlan pcp 0 prefix "[bri-NAM-TEST-10-C]" continue default accept all 2130 170688 vyos@BRI:~$ vyos@BRI:~$ show firewall bridge name TEST Ruleset Information --------------------------------- bridge Firewall "name TEST" Rule Action Protocol Packets Bytes Conditions ------- -------- ---------- --------- ------- -------------------------------------------------- 10 continue all 2130 170688 vlan pcp 0 prefix "[bri-NAM-TEST-10-C]" continue default accept all 2130 170688 vyos@BRI:~$ Inspect logs: .. code-block:: none vyos@BRI:~$ show log firewall bridge Dec 05 14:37:47 kernel: [bri-NAM-TEST-10-C]IN=eth1 OUT=eth2 ARP HTYPE=1 PTYPE=0x0800 OPCODE=1 MACSRC=50:00:00:04:00:00 IPSRC=10.11.11.101 MACDST=00:00:00:00:00:00 IPDST=10.11.11.102 Dec 05 14:37:48 kernel: [bri-NAM-TEST-10-C]IN=eth1 OUT=eth2 ARP HTYPE=1 PTYPE=0x0800 OPCODE=1 MACSRC=50:00:00:04:00:00 IPSRC=10.11.11.101 MACDST=00:00:00:00:00:00 IPDST=10.11.11.102 Dec 05 14:37:49 kernel: [bri-NAM-TEST-10-C]IN=eth1 OUT=eth2 ARP HTYPE=1 PTYPE=0x0800 OPCODE=1 MACSRC=50:00:00:04:00:00 IPSRC=10.11.11.101 MACDST=00:00:00:00:00:00 IPDST=10.11.11.102 ... vyos@BRI:~$ show log firewall bridge forward filter Dec 05 14:42:22 kernel: [bri-FWD-filter-default-D]IN=eth2 OUT=eth1 MAC=33:33:00:00:00:16:50:00:00:06:00:00:86:dd SRC=0000:0000:0000:0000:0000:0000:0000:0000 DST=ff02:0000:0000:0000:0000:0000:0000:0016 LEN=96 TC=0 HOPLIMIT=1 FLOWLBL=0 PROTO=ICMPv6 TYPE=143 CODE=0 Dec 05 14:42:22 kernel: [bri-FWD-filter-default-D]IN=eth2 OUT=eth1 MAC=33:33:00:00:00:16:50:00:00:06:00:00:86:dd SRC=0000:0000:0000:0000:0000:0000:0000:0000 DST=ff02:0000:0000:0000:0000:0000:0000:0016 LEN=96 TC=0 HOPLIMIT=1 FLOWLBL=0 PROTO=ICMPv6 TYPE=143 CODE=0