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Elastic Compute Service:ModifySecurityGroupPolicy

Last Updated:Apr 11, 2024

Modifies the internal access control policy of a basic security group. The internal access control policies of advanced security groups cannot be modified.

Operation description

Take note of the following items:

  • When InnerAccessPolicy is set to Accept for a security group, the instances in the security group can communicate with each other. In this case, the Accept internal access control policy takes precedence over user-created security group rules to keep instances in the security group accessible to each other.
  • When InnerAccessPolicy is set to Drop for a security group, the instances in the security group are isolated from each other. In this case, user-created security group rules take precedence over the Drop internal access control policy and can be used to allow access between the instances. For example, you can call the AuthorizeSecurityGroup operation to create an inbound security group rule that allows the instances in the security group to communicate with each other.
  • You can call the DescribeSecurityGroupAttribute operation to query the internal access policy of a security group.


OpenAPI Explorer automatically calculates the signature value. For your convenience, we recommend that you call this operation in OpenAPI Explorer.

Authorization information

There is currently no authorization information disclosed in the API.

Request parameters


The ID of the security group.


The region ID of the security group. You can call the DescribeRegions operation to query the most recent region list.


The internal access policy of the security group. Valid values:

  • Accept: All instances in the security group can communicate with each other.
  • Drop: All instances in the security group are isolated from each other.

The value of this parameter is not case-sensitive.


The client token that is used to ensure the idempotence of the request. You can use the client to generate the token, but you must make sure that the token is unique among different requests. The token can contain only ASCII characters and cannot exceed 64 characters in length. For more information, see How to ensure idempotence.


Response parameters


The request ID.



Sample success responses


  "RequestId": "CEF72CEB-54B6-4AE8-B225-F876FF7BA984"

Error codes

HTTP status codeError codeError messageDescription
400MissingParamter.RegionIdThe RegionId should not be null.The RegionId parameter is required.
400InvalidSecurityGroupId.MalformedThe SecurityGroupId is invalid. Only letters, numbers and underscores are supported. Maximum length is 100 characters.The specified SecurityGroupId parameter is invalid. The value can be up to 100 characters in length and can contain only letters, digits, and underscores (_).
400InvalidPolicy.MalformedThe Policy is invalid. Only 'Accept' and 'Drop' are supported. Ignore case.-
403InvalidOperation.ResourceManagedByCloudProduct%sYou cannot modify security groups managed by cloud services.
404InvalidSecurityGroupId.NotFoundThe specified SecurityGroupId does not exist.The specified security group does not exist in this account. Check whether the security group ID is correct.
404InvalidParameter.InnerAccessPolicyThe InnerAccessPolicy attribute of enterprise level security group can't be modified.-

For a list of error codes, visit the Service error codes.

Change history

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