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Cloud Enterprise Network:AssociateTransitRouterMulticastDomain

Last Updated:Aug 12, 2026

Associates a vSwitch in a virtual private cloud (VPC) with a multicast domain by calling the AssociateTransitRouterMulticastDomain operation so that resources in the VPC can communicate through multicast.

Operation description

  • A vSwitch can be associated with only one multicast domain. Make sure that the vSwitch to be associated is not already associated with another multicast domain. To disassociate a vSwitch from a multicast domain, see DisassociateTransitRouterMulticastDomain.

  • AssociateTransitRouterMulticastDomain is an asynchronous operation. After you send a request, the system returns a RequestId but the association between the vSwitch and the multicast domain is not yet complete. The association task continues to run in the background. You can call ListTransitRouterMulticastDomainAssociations to query the association status between the vSwitch and the multicast domain.

    • If the association status is Associating, the association between the vSwitch and the multicast domain is being established. In this state, you can only query the vSwitch but cannot perform other operations.

    • If the association status is Associated, the association between the vSwitch and the multicast domain is established.

  • The VPC to which the vSwitch belongs must be connected to an Enterprise Edition transit router. To create a VPC connection, see CreateTransitRouterVpcAttachment.

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RAM authorization

The table below describes the authorization required to call this API. You can define it in a Resource Access Management (RAM) policy. The table's columns are detailed below:

  • Action: The actions can be used in the Action element of RAM permission policy statements to grant permissions to perform the operation.

  • API: The API that you can call to perform the action.

  • Access level: The predefined level of access granted for each API. Valid values: create, list, get, update, and delete.

  • Resource type: The type of the resource that supports authorization to perform the action. It indicates if the action supports resource-level permission. The specified resource must be compatible with the action. Otherwise, the policy will be ineffective.

    • For APIs with resource-level permissions, required resource types are marked with an asterisk (*). Specify the corresponding Alibaba Cloud Resource Name (ARN) in the Resource element of the policy.

    • For APIs without resource-level permissions, it is shown as All Resources. Use an asterisk (*) in the Resource element of the policy.

  • Condition key: The condition keys defined by the service. The key allows for granular control, applying to either actions alone or actions associated with specific resources. In addition to service-specific condition keys, Alibaba Cloud provides a set of common condition keys applicable across all RAM-supported services.

  • Dependent action: The dependent actions required to run the action. To complete the action, the RAM user or the RAM role must have the permissions to perform all dependent actions.

Action

Access level

Resource type

Condition key

Dependent action

cen:AssociateTransitRouterMulticastDomain

update

*TransitRouterMulticastDomain

acs:cen:*:{#accountId}:centransitroutermulticast/{#centransitroutermulticastId}

None None

Request parameters

Parameter

Type

Required

Description

Example

ClientToken

string

No

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 client token can contain only ASCII characters.

123e4567-e89b-12d3-a456-426655440000

TransitRouterMulticastDomainId

string

Yes

The ID of the multicast domain.

tr-mcast-domain-91wpg6wbhchjeq****

TransitRouterAttachmentId

string

Yes

The ID of the VPC connection.

tr-attach-g3kz2k3u76amsk****

VSwitchIds

array

Yes

The list of vSwitch IDs.

string

Yes

The vSwitch ID.

You can associate up to 5 vSwitches at a time, and a multicast domain supports up to 10 associated vSwitches.

vsw-p0wxk12u6okfkr8xy****

DryRun

boolean

No

Specifies whether to perform a dry run. Valid values:

  • true: performs a dry run without associating the vSwitch with the multicast domain. The system checks the required parameters, request syntax, and business restrictions. If the request fails the dry run, an error message is returned. If the request passes the dry run, the error code DryRunOperation is returned.

  • false (default): performs a dry run and sends the request. If the request passes the dry run, the vSwitch is associated with the multicast domain.

false

Response elements

Element

Type

Description

Example

object

The response parameters.

RequestId

string

The request ID.

F88AC12C-943B-50E9-A344-4F8820BB07A7

Examples

Success response

JSON format

{
  "RequestId": "F88AC12C-943B-50E9-A344-4F8820BB07A7"
}

Error codes

HTTP status code

Error code

Error message

Description

400 InvalidMulticastDomain.NotFound The specified MulticastDomain is not found. The error message returned because the specified multicast domain does not exist.
400 IncorrectStatus.MulticastDomain The status of MulticastDomain is incorrect. The error message returned because the status of the specified multicast domain does not support this operation. Try again later.
400 InvalidAttachmentId.NotFound The specified AttachmentId is not found.
400 IllegalParam.AttachmentId The specified AttachmentId is illegal. The error message returned because the specified attachment ID is invalid.
400 IncorrectStatus.Attachment The status of Attachment is incorrect. The error message returned because the status of the attachment does not support this operation. Try again later.
400 MissingParam.VSwitchIds The parameter VSwitchIds is mandatory. The error message returned because the VSwitchIds parameter is not set.
400 InstanceNotExist The instance is not exist. The error message returned because the specified instance does not exist.
400 OperationUnsupported.CloudBoxVpc The specified CloudBoxVpc does not support the operation. The error message returned because the CloudBox VPC does not support this operation.
400 AssociationExist.VSwitchIds The association already exists. The error message returned because the specified resource is already associated with the vSwitch.
400 QuotaFull.VswitchPerMulticastDomain The number of vswitch associated with multicast domain has exceed the maximum value that can be created. The error message returned because the number of vSwitches associated with the multicast domain has reached the upper limit.
400 DryRunOperation Request validation has been passed with DryRun flag set. The error message returned because the dry run request passed the precheck.
400 OperationUnsupported.VpcRegion The specified Region is not support for this operation. The error message returned because this operation is not supported in the specified region.
400 OperationUnsupported.AdvancedFeature The specified vpc does not support the operation.
400 QuotaFull.MulticastDomainPerVpc The number of multicast domain that vpc associated has exceed the maximum value that can be associated. The number of multicast domain that vpc associated has exceed the maximum value that can be associated.
400 IllegalParam.VSwitchIds The parameter VSwitchIds is illegal. The parameter VSwitchIds is illegal.
400 InvalidParameter Invalid parameter. The error message returned because the parameter is set to an invalid value.
400 Unauthorized The AccessKeyId is unauthorized. The error message returned because you do not have the permissions to perform this operation.
400 InvalidParameter.TransitRouterAttachmentId The specified parameter TransitRouterAttachmentId is invalid.
400 InvalidParameter.TransitRouterMulticastDomainId The specified parameter TransitRouterMulticastDomainId is invalid. The parameter TransitRouterMulticastDomainId entered is illegal.

See Error Codes for a complete list.

Release notes

See Release Notes for a complete list.