This topic describes how to apply for a public endpoint for an RDS for SQL Server instance. Apsara for RDS supports two types of endpoints: internal endpoints and public endpoints. By default, the system provides you with an internal endpoint for connecting to your RDS instance. If you want to connect to your RDS instance through the Internet, you must apply for a public endpoint.

Internal and public endpoints

Endpoint type Description
Internal endpoint

The internal endpoint is generated by default.

Use the internal endpoint if all of the following conditions are met:

  • Your application is deployed on an ECS instance.
  • The ECS instance is located in the same region as your RDS instance.
  • The ECS instance has the same network type as your RDS instance.
The internal endpoint is recommended because accessing RDS through the intranet is most secure and delivers optimal performance.
Public endpoint You must manually apply for a pubic endpoint. You can also release it anytime.

Use the pubic endpoint if you cannot access RDS through the intranet. Specific scenarios are as follows:

  • An ECS instance accesses your RDS instance but the ECS instance is located in a different region or has a network type different from your RDS instance.
  • A server or computer outside Alibaba Cloud accesses your RDS instance.
  • The pubic endpoint and traffic are currently free of charge.
  • Using the pubic endpoint reduces security. Please exercise caution.
  • To guarantee high security and performance, we recommend that you migrate your application to an ECS instance that is in the same region and has the same network type as your RDS instance and then use the pubic endpoint.

Apply for a pubic endpoint

  1. Log on to the RDS console.
  2. In the upper-left corner, select the region where the RDS instance is located.
  3. Find the RDS instance and click its ID.
  4. In the left-side navigation pane, click Database Connection.
  5. Click Apply for Public Endpoint.
    Apply for Public Endpoint
  6. In the displayed dialog box, click OK.

    The pubic endpoint is generated.

  7. Optional. To change the pubic endpoint or port number, click Change Endpoint. In the displayed dialog box, select a connection type, set the pubic endpoint and port number, and click OK.
    • Connection Type: Select Public Endpoint.
      Note The Public Endpoint option is available only after you have applied for a pubic endpoint.
    • Endpoint: The endpoint contains 8 to 64 characters, including letters, digits, and hyphens (-). The prefix of the endpoint must start with a lowercase letter.
    • Port: The port number can be modified only when the RDS network type is classic network.

    Change Endpoint


API Description
AllocateInstancePublicConnection Used to apply for a pubic endpoint.