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Cloud Enterprise Network:CreateTransitRouterVpcAttachment

Last Updated:Jul 15, 2026

Calls the CreateTransitRouterVpcAttachment operation to connect a Virtual Private Cloud (VPC) instance to a transit router instance for private network peering.

Operation description

  • You can create a VPC connection on an Enterprise Edition transit router in the following two ways:

    • If you have already created an Enterprise Edition transit router instance in the target region, you can create a VPC connection by specifying VpcId, ZoneMappings.N.VSwitchId, ZoneMappings.N.ZoneId, TransitRouterId, and RegionId.

    • If no Enterprise Edition transit router instance exists in the target region, you can create a VPC connection by specifying VpcId, ZoneMappings.N.VSwitchId, ZoneMappings.N.ZoneId, CenId, and RegionId. The system performs automatic creation of an Enterprise Edition transit router instance when the VPC connection is created.

  • The CreateTransitRouterVpcAttachment operation is asynchronous. After you send a request, the system returns a VPC connection ID but the VPC connection is not yet created. The creation node continues to run in the background. You can invoke the ListTransitRouterVpcAttachments operation to query the status of the VPC connection.

    • If the VPC connection is in the Attaching state, the VPC connection is being created. In this state, you can only execute query operations on the VPC connection but cannot execute other operations.

    • If the VPC connection is in the Attached state, the VPC connection is created.

  • After a VPC connection is created, it is not associated with any transit router routing table for route learning or route forwarding by default.

Before you begin

Before you call this operation to create a VPC connection, make sure the following conditions are met:

  • The VPC instance has at least one VPC-connected instance in a zone supported by the Enterprise Edition transit router, and the VPC-connected instance has at least one idle IP address. For information about the regions and zones supported by Enterprise Edition transit routers, see Regions and zones supported by Enterprise Edition transit routers.

  • If you want to connect a cross-account network instance, obtain the cross-account authorization first. For more information, see Cross-account network instance authorization.

  • Fees are incurred after a VPC connection is created. Make sure you understand the billing rules. For more information, see Billing.

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Test

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:CreateTransitRouterVpcAttachment

create

CenInstance

acs:cen:*:{#accountId}:ceninstance/{#ceninstanceId}

TransitRouter

acs:cen:*:{#accountId}:centransitrouter/{#TransitRouterId}

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.

Note

If you do not specify this parameter, the system automatically uses the RequestId of the API request as the ClientToken. The RequestId may be different for each API request.

02fb3da4-130e-11e9-8e44-001****

CenId

string

No

The Cloud Enterprise Network (CEN) instance ID.

cen-j3jzhw1zpau2km****

TransitRouterId

string

No

The Enterprise Edition transit router instance ID.

tr-bp1su1ytdxtataupl****

RegionId

string

No

The region ID of the VPC instance.

You can invoke the DescribeChildInstanceRegions operation to query the region ID.

cn-hangzhou

TransitRouterAttachmentName

string

No

The name of the VPC connection.

The name can be empty or 1 to 128 characters in length, and cannot start with http:// or https://.

testname

TransitRouterAttachmentDescription

string

No

The description of the VPC connection.

The description can be empty or 1 to 256 characters in length, and cannot start with http:// or https://.

testname

VpcId

string

Yes

The VPC instance ID.

vpc-bp1kbjcre9vtsebo1****

VpcOwnerId

integer

No

The Alibaba Cloud account ID of the account to which the VPC instance belongs. The default value is the ID of the current Alibaba Cloud account that you use to log on.

Note

This parameter is required if you want to load a cross-account network instance.

1250123456123456

ChargeType

string

No

The billing method. Default value: POSTPAY, which specifies the pay-as-you-go billing method.

POSTPAY

DryRun

boolean

No

Specifies whether to perform a dry run, including permission and instance status verification. Valid values:

  • false (default): Sends a normal request and creates the VPC connection after the request passes the check.

  • true: Sends a check request. Only the check is performed, and the VPC connection is not created. The check items include whether required parameters are specified and the request format. If the check fails, the corresponding error is returned. If the check succeeds, the error code DryRunOperation is returned.

false

ZoneMappings

array<object>

Yes

Select a vSwitch instance in a zone supported by the Enterprise Edition transit router.

You can add up to 10 entries at a time.

object

No

The information about the zones supported by the Enterprise Edition transit router and the corresponding vSwitch instances.

VSwitchId

string

Yes

The ID of the vSwitch instance in a zone supported by the Enterprise Edition transit router.

You can specify vSwitch instances for up to 10 zones at a time.

vsw-bp1a214sbus8z3b54****

ZoneId

string

Yes

The ID of a zone supported by the Enterprise Edition transit router.

You can call the DescribeZones operation to query the zone ID.

You can specify up to 10 zones at a time.

cn-hangzhou-h

AutoPublishRouteEnabled

boolean

No

Specifies whether to allow the Enterprise Edition transit router to automatically forward routing entries to the VPC instance. In other words, specifies whether to publish route entries from the transit router to the VPC.

  • false (default): No.

  • true: Yes.

true

TransitRouterVPCAttachmentOptions

object

No

The list of feature attributes of the VPC connection (to be deprecated. Use the new parameter Options instead).

string

No

The feature attribute of the VPC connection (to be deprecated. Use the new parameter Options instead).

ipv6Support: specifies whether to enable IPv6.

  • enable: enables IPv6.

  • disable: disables IPv6.

Note

Before you enable IPv6 for a VPC connection, make sure that the VPC instance and its associated vSwitch instances have IPv6 enabled. For more information, see AllocateVpcIpv6Cidr and CreateVSwitchCidrReservation.

disable

Tag

array<object>

No

The list of tags.

You can specify up to 20 tags at a time.

object

No

The tag.

Key

string

No

The tag key of the resource.

The tag key cannot be an empty string. It can be up to 64 characters in length and cannot start with aliyun or acs:. It cannot contain http:// or https://.

You can specify up to 20 tag keys at a time.

tagtest

Value

string

No

The tag value of the resource.

The tag value can be an empty string or up to 128 characters in length. It cannot start with aliyun or acs:. It cannot contain http:// or https://.

Each tag key corresponds to one tag value. You can specify up to 20 tag values at a time.

tagtest

Options

object

No

The collection of feature attributes.

Ipv6Support

string

No

Specifies whether IPv6 is supported.

  • disable (default): No.

  • enable: Yes.

enable

ApplianceModeSupport

string

No

Specifies whether to enable the appliance mode for traffic redirection.

  • disable (default): No.

  • enable: Yes.

enable

Response elements

Element

Type

Description

Example

object

The response parameters.

TransitRouterAttachmentId

string

The ID of the VPC connection.

tr-attach-ia340z7xis7t5s****

RequestId

string

The request ID.

C087A369-82B9-43EF-91F4-4B63A9C6E6B6

Examples

Success response

JSON format

{
  "TransitRouterAttachmentId": "tr-attach-ia340z7xis7t5s****",
  "RequestId": "C087A369-82B9-43EF-91F4-4B63A9C6E6B6"
}

Error codes

HTTP status code

Error code

Error message

Description

400 OperationUnsupported.TransitRouterRegionId The specified TransitRouterRegion does not support the operation.
400 NoPermission.AliyunServiceRoleForCEN You are not authorized to create the service linked role. Role Name: AliyunServiceRoleForCEN. Service Name: cen.aliyuncs.com. Make sure that the user has been granted the ram:CreateServiceLinkedRole permission. The error message because you do not have the permissions to create the service-linked role whose role name is AliyunServiceRoleForCEN and service name is cen.aliyuncs.com. You must acquire the ram:CreateServiceLinkedRole permission before you can create the service-linked role.
400 IllegalParam.RegionId The Specified Parameter RegionId is illegal The error message returned because the specified region is invalid.
400 MissingParam.CenIdOrRegionId Either CenId or RegionId must be specified. The error message returned because the CenId or RegionId parameter is not set.
400 IllegalParam.ZoneId The specified ZoneId is illegal. The error message returned because the specified zone is invalid.
400 IllegalParam.ChargeType The specified ChargeType is illegal. The error message returned because the specified billing method is invalid.
400 InvalidTransitRouterId.NotFound The specified TransitRouterId is not found. The error message returned because the specified transit router does not exist.
400 IncorrectStatus.VpcResource The resource is not in a valid state for the attachment operation. The error message returned because this operation is not supported when the specified VPC is in an unstable state. Wait until all operations related to the VPC are completed.
400 IncorrectStatus.Vpc The resource is not in a valid state for the attachment operation. The error message returned because the status of the VPC does not support this operation. Try again later.
400 IncorrectStatus.VpcOrVswitch The Vpc Or Vswith is not in a valid state for the attachment operation. The error message returned because the status of the VPC or vSwitch does not support this operation. Try again later.
400 OperationNotSupport.VpcAutoRoutesPublish Auto publish vpc routes is not supported in this region. The error message returned because automatic route advertising for VPCs is not supported in the specified region.
400 InvalidOperation.VpnAssociated The operation is not supported because the VPC is associated with VPN. The error message returned because the specified VPC is associated with a VPN.
400 Forbbiden.TransitRouterServiceNotOpen The user has not open transit router service. The error message returned because the transit router is disabled. Enable the transit router and try again.
400 IllegalParam.ZoneMappings The Specified Parameter ZoneMappings is illegal The error message returned because the specified zone mappings (ZoneMappings) is invalid.
400 OperationUnsupported.TransitRouterType The specified TransitRouterType does not support the operation. The error message returned because this operation is not supported by the specified type of transit router.
400 InvalidCenId.NotFound CenId is not found. The error message returned because the specified CEN instance does not exist.
400 IllegalParam.VSwitchId VSwitchId is illegal. The error message returned because the specified vSwitch ID is invalid.
400 IncorrectStatus.TransitRouterInstance The status of TransitRouter is incorrect. The error message returned because the transit router is in an invalid state.
400 OperationUnsupported.CenFullLevel CEN full level does not support TransitRouter The error message returned because CEN instances of the Full type do not support Enterprise Edition transit routers.
400 IllegalParam.ServiceMode ServiceMode is illegal. The error message returned because the specified service mode is invalid.
400 QuotaFull.ChildInstanceRelatedCen The childinstance has exceed the quota of the times that a childinstance can be attached as an attachment. The error message returned because the number of CEN instances to which the instance is attached has reached the upper limit. You cannot attach the instance to more CEN instances.
400 OperationUnsupported.CloudBoxVswNotSupport Cloud Box vsw does not support. The error message returned because the instance cannot be connected to the CloudBox vSwitch.
400 IncorrectStatus.TransitRouter The status of TransitRouter is incorrect. The error message returned because the status of the transit router does not support this operation. Try again later.
400 Duplicated.ZoneMapping The parameter ZoneMapping is duplicated. The error message returned because the zone mapping contains duplicate routes.
400 QuotaExceeded.CenQuotaVpcAttachPerTransitRouter The maximum number of VPC attachment per Transit Router is exceeded. The error message returned because the specified number of VPCs to be attache to the transit router exceeds the upper limit.
400 IncorrectStatus.VpcRouteTable The VPC route table is not in a desired state. The error message returned because the VPC route table is in an unstable state. Try again later.
400 InvalidStatus.VpcAttachedFullModeCen The VPC has been attached to another CEN instance whose protection level is FULL. The error message returned because the specified VPC is already attached to a CEN instance whose protection level is FULL. The VPC cannot be attached to other CEN instances.
400 Forbbiden.AttachChildInstanceAcrossBid VPCs that belong to another BID cannot be associated. You need to apply for cross-BID attaching. The error message returned because you cannot associate with VPCs that belong to another BID.
400 InvalidOperation.VpcAutoRoutesPublishInOtherCEN The specified VPC already has its routes synchronized with another CEN instance. The error message returned because this operation is not supported when route synchronization is enabled between the current VPC and another CEN instance.
400 QuotaExceeded.VpcAutoRoutesPublishPerTransitRouter The number of VPCs that have route synchronization enabled has reached the upper limit. The error message returned because the number of VPCs that have route synchronization enabled has reached the upper limit.
400 InsufficientIpAddr.vsw Insufficient available IP addresses in the vSwitch. The error message returned because the number of available IP addresses in the vSwitch is insufficient.
400 Forbidden.ResourceOwnerTransitRouterServiceNotOpen The resource owner user has not opened transit router service. The transit router service for the resource owner's account is not currently opened. Please inform them to open the transit router service and then try again.
400 IllegalParam.TransitRouterRegionId TransitRouterRegionId is illegal. The error message returned because the specified transit router region ID (TransitRouterRegionId) is invalid.
400 InvalidTransitRouterMode.NeedUpgrade TransitRouter need to upgrade. The error message returned because the specified transit router mode is not supported.
400 IllegalParam.Ipv6Support Ipv6Support is illegal. Valid Values are [enable, disable]. The Ipv6Support value of the request parameter is invalid. The valid value is enable or disable.
400 OperationFailed.VSwitchNotFound The specified vswitch not found. The specified vswitch not found.
400 OperationFailed.VSwitchIpv6CidrNotAllocated The specified vswitch does not have IPv6 address allocated. The specified vswitch does not have IPv6 address allocated.
400 Forbidden.ResourceOwnerTransitRouterServiceExpired The transit router service of the account to which the resource belongs has been suspended due to arrears. Please notify the other party to renew the service and try again. The transit router service of the account to which the resource belongs has been suspended. Please notify the other party to renew the service and try again.
400 Forbidden.TransitRouterServiceExpired The transit router service is out of service. The transit router service has been suspended due for payment. Please renew the service and try again.
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.ResourceType The specified parameter ResourceType is invalid.
400 ParamExclusive.TransitRouterVPCAttachmentOptionsAndOptions When creating or modifying a VPC attachment, the input parameter TransitRouterVPCAttachmentOptions and Options cannot be used at the same time. When creating or modifying a VPC attachment, the input parameter TransitRouterVPCAttachmentOptions and Options cannot be used at the same time.
400 InvalidParameter.ApplianceModeSupport The specified parameter ApplianceModeSupport is invalid. The parameter ApplianceModeSupport entered is illegal.
400 InvalidParameter.Ipv6Support The specified parameter Ipv6Support is invalid. The parameter Ipv6Support entered is illegal.
400 INVALID_OPERATION_RESOURCE_NOT_SUPPORT_APPLIANCE_MODE Only VPC attachment support appliance mode. Only VPC attachment support appliance mode.
400 InvalidParameter.TagValue The specified parameter TagValue is invalid. The input parameter Tag Value is invalid.
404 InvalidVSwitchId.NotFound The specified VSwitchId is not found. The error message returned because the specified vSwitch ID does not exist.
409 InvalidOperation.CenInstanceStatus The CEN instance is not in a valid state for the operation. The error message returned because the status of the CEN instance does not support this operation.
409 IncorrectStatus.VpcSwitch The resource is not in a valid state for the attachment operation.

See Error Codes for a complete list.

Release notes

See Release Notes for a complete list.