[Yandex Cloud documentation](../../../index.md) > [Yandex DataLens](../../index.md) > Connections > Overview

# Connecting to a data source in Yandex DataLens

_Connections_ contain information about data source access parameters, such as the DB host IP address and port.

In a single connection, only one data source can be described.

You can create [_datasets_](../../dataset/index.md) based on connections.

The following connection types are available in DataLens:


* Databases: {#db}

  * [ClickHouse®](../../operations/connection/create-clickhouse.md)
  * [PostgreSQL](../../operations/connection/create-postgresql.md)
  * [MySQL®](../../operations/connection/create-mysql.md)
  * [YDB](../../operations/connection/create-ydb.md)
  * [YTsaurus CHYT](../../operations/connection/chyt/create-chyt.md)
  * [Greenplum®](../../operations/connection/create-greenplum.md)
  * [MS SQL Server](../../operations/connection/create-mssql-server.md)
  * [Oracle Database](../../operations/connection/create-oracle.md)
  * [StarRocks](../../operations/connection/create-starrocks.md)
  * [Trino](../../operations/connection/create-trino.md)
  * [Prometheus](../../operations/connection/create-prometheus.md)
  * [Snowflake](../../operations/connection/create-snowflake.md)

* Files and services:

  * [Files](../../operations/connection/create-file.md)
  * [Yandex Documents](../../operations/connection/create-yadocs.md)
  * [Google Sheets](../../operations/connection/create-google-sheets.md)
  * [Yandex Query](../../operations/connection/create-yandex-query.md)
  * [Metrica](../../operations/connection/create-metrica-api.md)
  * [AppMetrica](../../operations/connection/create-appmetrica.md)
   * [Yandex Cloud Billing](../../operations/connection/create-cloud-billing.md)
   * [Yandex Monitoring](../../operations/connection/create-monitoring.md)
  * [DataLens Usage Analytics](../../operations/connection/create-usage-tracking.md)
  * [Connecting API Connector](../../operations/connection/create-api-connector.md)
   * [SpeechSense](../../operations/connection/create-speechsense.md)


* Partner connections:

  * [1C Extractor](../../operations/connection/create-extractor1c.md)
  * [Bitrix24](../../operations/connection/create-bitrix24.md)
  * [Analystics podcasts](../../operations/connection/create-podcasts.md)
  * [Suggest your partner connector](../../operations/marketplace/create-connector-for-partners.md)








## Connecting an external database {#external-db-connection}

Yandex Cloud holds no responsibility for configuring a remote connection on an external database server side. When connecting an external database that is not a Yandex Cloud resource:

* Make sure the database uses an SSL certificate signed by a SSL certificate authority. You will not be able to create a connection in DataLens if the database uses a self-signed SSL certificate.
* Grant database access to the following DataLens IP ranges (`/` is followed by the subnet mask length):

  {% list tabs group=ip_address %}

  - ipv4 {#ipv4}

    * `178.154.242.176/28`
    * `178.154.242.192/28`
    * `178.154.242.208/28`
    * `178.154.242.128/28`
    * `178.154.242.144/28`
    * `178.154.242.160/28`
    * `130.193.60.0/28`

  - ipv6 {#ipv6}

    * `2a02:6b8:c03:500:0:f83d:a987:0/112`
    * `2a02:6b8:c02:900:0:f83d:a987:0/112`
    * `2a02:6b8:c0e:500:0:f83d:a987:0/112`
    * `2a02:6b8:c41:1300:0:f83d:a987:0/112`

  {% endlist %}


## Access management {#access-management}

You can configure connection permissions. For more information, see [Managing access to Yandex DataLens](../../security/index.md).


_ClickHouse® is a registered trademark of [ClickHouse, Inc](https://clickhouse.com)._