# Forward

*Forward* is the protocol used by [Fluent Bit](http://fluentbit.io) and [Fluentd](http://www.fluentd.org) to route messages between peers. This plugin implements the input service to listen for Forward messages.

## Configuration Parameters

The plugin supports the following configuration parameters:

| Key                 | Description                                                                                                                                                                                                                                                                                                                                                             | Default |
| ------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------- |
| Listen              | Listener network interface.                                                                                                                                                                                                                                                                                                                                             | 0.0.0.0 |
| Port                | TCP port to listen for incoming connections.                                                                                                                                                                                                                                                                                                                            | 24224   |
| Unix\_Path          | Specify the path to unix socket to receive a Forward message. If set, `Listen` and `Port` are ignored.                                                                                                                                                                                                                                                                  |         |
| Unix\_Perm          | Set the permission of the unix socket file. If `Unix_Path` is not set, this parameter is ignored.                                                                                                                                                                                                                                                                       |         |
| Buffer\_Max\_Size   | Specify the maximum buffer memory size used to receive a Forward message. The value must be according to the [Unit Size](https://docs.fluentbit.io/manual/1.9/administration/configuring-fluent-bit/unit-sizes) specification.                                                                                                                                          | 6144000 |
| Buffer\_Chunk\_Size | By default the buffer to store the incoming Forward messages, do not allocate the maximum memory allowed, instead it allocate memory when is required. The rounds of allocations are set by *Buffer\_Chunk\_Size*. The value must be according to the [Unit Size ](https://docs.fluentbit.io/manual/1.9/administration/configuring-fluent-bit/unit-sizes)specification. | 1024000 |
| Tag\_Prefix         | Prefix incoming tag with the defined value.                                                                                                                                                                                                                                                                                                                             |         |

## Getting Started

In order to receive Forward messages, you can run the plugin from the command line or through the configuration file as shown in the following examples.

### Command Line

From the command line you can let Fluent Bit listen for *Forward* messages with the following options:

```bash
$ fluent-bit -i forward -o stdout
```

By default the service will listen an all interfaces (0.0.0.0) through TCP port 24224, optionally you can change this directly, e.g:

```bash
$ fluent-bit -i forward -p listen="192.168.3.2" -p port=9090 -o stdout
```

In the example the Forward messages will only arrive through network interface under 192.168.3.2 address and TCP Port 9090.

### Configuration File

In your main configuration file append the following *Input* & *Output* sections:

```python
[INPUT]
    Name              forward
    Listen            0.0.0.0
    Port              24224
    Buffer_Chunk_Size 1M
    Buffer_Max_Size   6M

[OUTPUT]
    Name   stdout
    Match  *
```

## Testing

Once Fluent Bit is running, you can send some messages using the *fluent-cat* tool (this tool is provided by [Fluentd](http://www.fluentd.org):

```bash
$ echo '{"key 1": 123456789, "key 2": "abcdefg"}' | fluent-cat my_tag
```

In [Fluent Bit](http://fluentbit.io) we should see the following output:

```bash
$ bin/fluent-bit -i forward -o stdout
Fluent-Bit v0.9.0
Copyright (C) Treasure Data

[2016/10/07 21:49:40] [ info] [engine] started
[2016/10/07 21:49:40] [ info] [in_fw] binding 0.0.0.0:24224
[0] my_tag: [1475898594, {"key 1"=>123456789, "key 2"=>"abcdefg"}]
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.fluentbit.io/manual/1.9/pipeline/inputs/forward.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.