---
title: "iptables parser"
url: "https://axoflow.com/docs/axosyslog-core/4.28/chapter-parsers/parser-iptables/"
last_modified: "2026-08-05T15:08:09+02:00"
---

> For the complete documentation index, see [llms.txt](https://axoflow.com/docs/axosyslog-core/4.28/llms.txt).

# iptables parser

The iptables parser can parse the log messages of the iptables command.

FilterX has no iptables parser, but you can reimplement this one in a FilterX block. For details, see [Create an iptables parser](https://axoflow.com/docs/axosyslog-core/4.28/filterx/index.md#create-an-iptables-parser).

## Prerequisites

- AxoSyslog version 3.16 or later.
- Install the `axosyslog-scl` package on [Debian/Ubuntu](https://axoflow.com/docs/axosyslog-core/4.28/install/debian-ubuntu/index.md). On [RHEL and compatible distributions](https://axoflow.com/docs/axosyslog-core/4.28/install/rhel-fedora-almalinux/index.md), the SCL files are part of the `axosyslog` base package.

  Your configuration must also contain `@include "scl.conf"`, which the default configuration file already does. If the SCL files are missing, AxoSyslog fails to start with an [`unexpected LL_IDENTIFIER` error](https://axoflow.com/docs/axosyslog-core/4.28/chapter-troubleshooting-syslog-ng/unexpected-ll-identifier/index.md).

  ```shell
  @include "scl.conf"
  ```

  The `iptables-parser()` driver is a reusable configuration snippet (SCL). For details on using or writing such configuration snippets, see [Reusing configuration blocks](https://axoflow.com/docs/axosyslog-core/4.28/chapter-configuration-file/large-configs/config-blocks/index.md). You can find its source in [scl/iptables/iptables.conf](https://github.com/axoflow/axosyslog/blob/main/scl/iptables/iptables.conf) on GitHub.

## Declaration:

```shell
   @version: 4.28
    @include "scl.conf"
    log {
        source { system(); };
        parser { iptables-parser(); };
        destination { ... };
    };
```

## prefix()

|  |  |
| --- | --- |
| Synopsis: | prefix() |

*Description:* Insert a prefix before the name part of the parsed name-value pairs to help further processing. For example:

- To insert the `my-parsed-data.` prefix, use the `prefix(my-parsed-data.)` option.
- To refer to a particular data that has a prefix, use the prefix in the name of the macro, for example, `${my-parsed-data.name}`.
- If you forward the parsed messages using the IETF-syslog protocol, you can insert all the parsed data into the SDATA part of the message using the `prefix(.SDATA.my-parsed-data.)` option.

Names starting with a dot (for example, `.example`) are reserved for use by AxoSyslog. If you use such a macro name as the name of a parsed value, it will attempt to replace the original value of the macro (note that only soft macros can be overwritten, see [Hard versus soft macros](https://axoflow.com/docs/axosyslog-core/4.28/chapter-manipulating-messages/customizing-message-format/macros-hard-vs-soft/index.md) for details). To avoid such problems, use a prefix when naming the parsed values, for example, `prefix(my-parsed-data.)`

By default, `iptables-parser()` uses the `.iptables.` prefix. To modify it, use the following format:

```shell
   parser {
        iptables-parser(prefix("myprefix."));
    };
```

Last modified August 5, 2026: [Small fixes and deduplications (99cac43a)](https://github.com/axoflow/axosyslog-core-docs/commit/99cac43a517770299b97c7ed360eb87af9fef5ab)