# Configuration Introduction

How the Magic Happens
{: .subtitle }

![Configuration](../assets/img/static-dynamic-configuration.png)

Configuration in Traefik can refer to two different things:
   
- The fully dynamic routing configuration (referred to as the _dynamic configuration_)
- The startup configuration (referred to as the _static configuration_)

Elements in the _static configuration_ set up connections to [providers](../../providers/overview/) and define the [entrypoints](../../routing/entrypoints/) Traefik will listen to (these elements don't change often).

The _dynamic configuration_ contains everything that defines how the requests are handled by your system.
This configuration can change and is seamlessly hot-reloaded, without any request interuption or connection loss.    

!!! warning "Incompatible Configuration"
    Please be aware that the old configurations for Traefik v1.X are NOT compatible with the v2.X config as of now.
    If you're testing out v2, please ensure you are using a v2 configuration.

## The Dynamic Configuration 

Traefik gets its _dynamic configuration_ from [providers](../providers/overview.md): wether an orchestrator, a service registry, or a plain old configuration file. Since this configuration is specific to your infrastructure choices, we invite you to refer to the [dedicated section of this documentation](../providers/overview.md).

!!! Note 
   
    In the [Quick Start example](../getting-started/quick-start.md), the dynamic configuration comes from docker in the form of labels attached to your containers.
    
!!! Note
    
    HTTPS Certificates also belong to the dynamic configuration. You can add / update / remove them without restarting your Traefik instance. 
 
## The Static Configuration

There are three different locations where you can define static configuration options in Traefik:

- In a key-value store
- In the command-line arguments
- In a configuration file

If you don't provide a value for a given option, default values apply.

!!! important "Precedence Order"

    The following precedence order applies for configuration options: key-value > command-line > configuration file.
    
    It means that arguments override configuration file, and key-value store overrides arguments.
    
!!! important "Default Values"

    Some root options are enablers: they set default values for all their children. 
    
    For example, the `--providers.docker` option enables the docker provider.
    Once positioned, this option sets (and resets) all the default values under the root `providers.docker`.
    If you define child options using a lesser precedence configuration source, they will be overwritten by the default values.  
    
### Configuration File

At startup, Traefik searches for a file named `traefik.toml` in `/etc/traefik/`, `$HOME/.traefik/`, and `.` (_the working directory_).

You can override this using the `configFile` argument.

```bash
traefik --configFile=foo/bar/myconfigfile.toml
```

### Arguments

Use `traefik --help` to get the list of the available arguments.

### Key-Value Stores

Traefik supports several Key-value stores:

- [Consul](https://consul.io)
- [etcd](https://coreos.com/etcd/)
- [ZooKeeper](https://zookeeper.apache.org/)
- [boltdb](https://github.com/boltdb/bolt)

## Available Configuration Options

All the configuration options are documented in their related section.

You can browse the available features in the menu, the [providers](../providers/overview.md), or the [routing section](../routing/overview.md) to see them in action.