Iptables module

This is a module for iptables and ip6tables logs. It parses logs received over the network via syslog or from a file. Also, it understands the prefix added by some Ubiquiti firewalls, which includes the rule set name, rule number and the action performed on the traffic (allow/deny).

When you run the module, it performs a few tasks under the hood:

• Sets the default input to syslog and binds to localhost port 9001 (but don’t worry, you can override the defaults).
• Uses an ingest pipeline to parse and process the log lines, shaping the data into a structure suitable for visualizing in Kibana.
• Deploys dashboards for visualizing the log data.

You can further refine the behavior of the iptables module by specifying variable settings in the modules.d/iptables.yml file, or overriding settings at the command line.

You must enable at least one fileset in the module. Filesets are disabled by default.

The module is by default configured to run via syslog on port 9001. However it can also be configured to read from a file path. See the following example.

- module: iptables
  log:
    enabled: true
    var.paths: ["/var/log/iptables.log"]
    var.input: "file"

Each fileset has separate variable settings for configuring the behavior of the module. If you don’t specify variable settings, the iptables module uses the defaults.

For advanced use cases, you can also override input settings. See Override input settings.

var.paths

An array of glob-based paths that specify where to look for the log files. All patterns supported by Go Glob are also supported here. For example, you can use wildcards to fetch all files from a predefined level of subdirectories: /path/to/log/*/*.log. This fetches all .log files from the subfolders of /path/to/log. It does not fetch log files from the /path/to/log folder itself. If this setting is left empty, Filebeat will choose log paths based on your operating system.

var.syslog_host

The interface to listen to UDP based syslog traffic. Defaults to localhost. Set to 0.0.0.0 to bind to all available interfaces.

var.syslog_port

The UDP port to listen for syslog traffic. Defaults to 9001

var.tags

A list of tags to include in events. Including forwarded indicates that the events did not originate on this host and causes host.name to not be added to events. Defaults to [iptables, forwarded].

This module parses logs that don’t contain time zone information. For these logs, Filebeat reads the local time zone and uses it when parsing to convert the timestamp to UTC. The time zone to be used for parsing is included in the event in the event.timezone field.

To disable this conversion, the event.timezone field can be removed with the drop_fields processor.

If logs are originated from systems or applications with a different time zone to the local one, the event.timezone field can be overwritten with the original time zone using the add_fields processor.

See Processors for information about specifying processors in your config.

This module comes with sample dashboards showing geolocation and network protocols used. One for all iptables logs:

and one specific for Ubiquiti Firewall logs:

For a description of each field in the module, see the exported fields section.