OpenSearch uses HTTP settings to configure communication with external clients through the REST API and transport settings for internal node-to-node communication within OpenSearch.
To learn more about static and dynamic settings, see [Configuring OpenSearch]({{site.url}}{{site.baseurl}}/install-and-configure/configuring-opensearch/index/).
OpenSearch supports the following common network settings:
-`network.host` (Static, list): Binds an OpenSearch node to an address. Use `0.0.0.0` to include all available network interfaces, or specify an IP address assigned to a specific interface. The `network.host` setting is a combination of `network.bind_host` and `network.publish_host` if they are the same value. An alternative to `network.host` is to configure `network.bind_host` and `network.publish_host` separately as needed. See [Advanced network settings](#advanced-network-settings).
-`http.port` (Static, single value or range): Binds an OpenSearch node to a custom port or a range of ports for HTTP communication. You can specify an address or a range of addresses. Default is `9200-9300`.
-`transport.port` (Static, single value or range): Binds an OpenSearch node to a custom port for communication between nodes. You can specify an address or a range of addresses. Default is `9300-9400`.
## Advanced network settings
OpenSearch supports the following advanced network settings:
-`network.bind_host` (Static, list): Binds an OpenSearch node to an address or addresses for incoming connections. Default is the value in `network.host`.
-`network.publish_host` (Static, list): Specifies an address or addresses that an OpenSearch node publishes to other nodes in the cluster so that they can connect to it.
## Advanced HTTP settings
OpenSearch supports the following advanced network settings for HTTP communication:
-`http.host` (Static, list): Sets the address of an OpenSearch node for HTTP communication. The `http.host` setting is a combination of `http.bind_host` and `http.publish_host` if they are the same value. An alternative to `http.host` is to configure `http.bind_host` and `http.publish_host` separately as needed.
-`http.bind_host` (Static, list): Specifies an address or addresses to which an OpenSearch node binds to listen for incoming HTTP connections.
-`http.publish_host` (Static, list): Specifies an address or addresses that an OpenSearch node publishes to other nodes for HTTP communication.
-`http.compression` (Static, Boolean): Enables support for compression using `Accept-Encoding` when applicable. When `HTTPS` is enabled, the default is `false`, otherwise, the default is `true`. Disabling compression for HTTPS helps mitigate potential security risks, such as `BREACH` attacks. To enable compression for HTTPS traffic, explicitly set `http.compression` to `true`.
OpenSearch supports the following advanced network settings for transport communication:
-`transport.host` (Static, list): Sets the address of an OpenSearch node for transport communication. The `transport.host` setting is a combination of `transport.bind_host` and `transport.publish_host` if they are the same value. An alternative to `transport.host` is to configure `transport.bind_host` and `transport.publish_host` separately as needed.
-`transport.bind_host` (Static, list): Specifies an address or addresses to which an OpenSearch node binds to listen for incoming transport connections.
-`transport.publish_host` (Static, list): Specifies an address or addresses that an OpenSearch node publishes to other nodes for transport communication.
The default OpenSearch transport is provided by the `transport-netty4` module and uses the [Netty 4](https://netty.io/) engine for both internal TCP-based communication between nodes in the cluster and external HTTP-based communication with clients. This communication is fully asynchronous and non-blocking. However, there are other transport plugins available that can be used interchangeably:
Plugin | Description
:---------- | :--------
`transport-nio` | The OpenSearch transport based on Java NIO. <br> Installation: `./bin/opensearch-plugin install transport-nio`<br> Configuration (using `opensearch.yml`): <br>`transport.type: nio-transport`<br>`http.type: nio-http-transport`
`transport-reactor-netty4` | The OpenSearch HTTP transport based on [Project Reactor](https://github.com/reactor/reactor-netty) and Netty 4 (**experimental**) <br> Installation: `./bin/opensearch-plugin install transport-reactor-netty4`<br> Configuration (using `opensearch.yml`): <br>`http.type: reactor-netty4`
