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Cloud Enterprise Network:CreateTransitRouterVpcAttachment

Last Updated:Sep 15, 2026

Calls the CreateTransitRouterVpcAttachment operation to attach a Virtual Private Cloud (VPC) instance to an Enterprise Edition transit router instance to enable private network peering. After the attachment is created, the transit router instance helps you implement private network connectivity through forwarding and routing.

Operation description

  • You can create a VPC attachment for an Enterprise Edition transit router in two ways:

    • If you have already created an Enterprise Edition transit router instance in the target region, specify VpcId, ZoneMappings.N.VSwitchId, ZoneMappings.N.ZoneId, TransitRouterId, and RegionId to create the VPC attachment.

    • If you have not created an Enterprise Edition transit router instance in the target region, specify VpcId, ZoneMappings.N.VSwitchId, ZoneMappings.N.ZoneId, CenId, and RegionId to create the VPC attachment. The system uses automatic creation to create an Enterprise Edition transit router instance when you create the VPC attachment.

  • CreateTransitRouterVpcAttachment is an asynchronous operation. The system returns a VPC attachment ID before the VPC attachment is created. The creation task runs in the background. Call ListTransitRouterVpcAttachments to query the status of the VPC attachment.

    • When the VPC attachment is in the Attaching state, the VPC attachment is being created. In this state, you can only query the VPC attachment and cannot execute other operations.

    • When the VPC attachment is in the Attached state, the VPC attachment is created.

  • After a VPC attachment is created, it does not associate with any transit router route table for route learning relationships or forwarding relationships by default.

Before you begin

Before you call this operation to create a VPC attachment, make sure that the following requirements are met:

  • The VPC instance has at least one vSwitch instance with at least one available IP address in a zone supported by the Enterprise Edition transit router. 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 attach a VPC-connected instance that belongs to a different account, obtain cross-account authorization first. For more information, see Cross-account VPC-connected instance authorization.

  • Creating a VPC attachment incurs fees. Make sure that 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.

Generate a unique value from your client for this parameter. ClientToken supports only ASCII characters.

Note

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

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

CenId

string

No

The instance ID of the Cloud Enterprise Network (CEN).

cen-j3jzhw1zpau2km****

TransitRouterId

string

No

The instance ID of the Enterprise Edition transit router.

tr-bp1su1ytdxtataupl****

RegionId

string

No

The ID of the region where the VPC instance is deployed.

You can call DescribeChildInstanceRegions to query region IDs.

cn-hangzhou

TransitRouterAttachmentName

string

No

The name of the VPC attachment.

The name can be left empty or can contain 1 to 128 characters. It cannot start with http:// or https://.

testname

TransitRouterAttachmentDescription

string

No

The description of the VPC attachment.

The description can be left empty or can contain 1 to 256 characters. It cannot start with http:// or https://.

testname

VpcId

string

Yes

The instance ID of the VPC.

vpc-bp1kbjcre9vtsebo1****

VpcOwnerId

integer

No

The ID of the Alibaba Cloud account to which the VPC instance belongs. The default value is the ID of the current logon Alibaba Cloud account.

Note

This parameter is required if you want to attach a network instance that belongs to a different account.

1250123456123456

ChargeType

string

No

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

POSTPAY

DryRun

boolean

No

Specifies whether to perform a dry run on the request, including permission checks and instance status validation. Valid values:

  • false (default): sends a normal request and creates a VPC after the check passes. Use this value to create a VPC.

  • true: sends a dry run request for validation only without creating the VPC attachment. The check includes whether required parameters are specified and whether the request format is valid. If the check fails, the corresponding error is returned. If the check passes, 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 vSwitch instance in a zone supported by the Enterprise Edition transit router.

You can select 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 DescribeZones to query zone IDs.

You can select up to 10 zones at a time.

cn-hangzhou-h

AutoPublishRouteEnabled

boolean

No

Specifies whether the Enterprise Edition transit router automatically publishes route entries to the VPC instance.

  • false (default): does not automatically publish route entries.

  • true: automatically publishes route entries.

true

TransitRouterVPCAttachmentOptions

object

No

The list of feature attributes for the VPC attachment (to be deprecated — use the new Options parameter instead).

string

No

The feature attribute for the VPC attachment (to be deprecated — use the new Options parameter instead).

ipv6Support: specifies whether to enable IPv6.

  • enable: enables IPv6.

  • disable: shutdown of IPv6. Disables IPv6 for the attachment.

Note

Before enabling IPv6 for a VPC attachment, 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.

If this parameter is specified, it cannot be an empty string. The tag key 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.

If this parameter is specified, it cannot be empty. The tag value can be up to 128 characters in length and 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 key-value pairs at a time.

tagtest

Options

object

No

The collection of feature attributes.

ApplianceModeSupport

string

No

Specifies whether to enable the network appliance traffic redirection mode.

  • disable (default): disabled.

  • enable: enabled.

enable

Ipv6Support

string

No

Specifies whether to enable IPv6 support.

  • disable (default): disabled.

  • enable: enabled.

enable

Response elements

Element

Type

Description

Example

object

The response result.

RequestId

string

The request ID.

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

TransitRouterAttachmentId

string

The ID of the VPC attachment.

tr-attach-ia340z7xis7t5s****

Examples

Success response

JSON format

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

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. The ResourceType specified by the user is illegal.
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.
400 InvalidParameter.CenBandwidthPackageId The specified parameter CenBandwidthPackageId is invalid. The parameter CenBandwidthPackageId entered is illegal.
400 InvalidParameter.CenId The specified parameter CenId is invalid. The entered parameter CenId is invalid.
400 InvalidParameter.TransitRouterId The specified parameter TransitRouterId is invalid. The parameter TransitRouterId entered is illegal.
400 InvalidParameter.AssociateRouteTableId The specified parameter AssociateRouteTableId is invalid. The parameter AssociateRouteTableId entered is illegal.
400 OperationFailed.PostPay95BwpNotAllowEnterpriseTr Cbn with post pay 95 bandwidth package does not allow enterprise tr. Cbn with post pay 95 bandwidth package does not allow enterprise tr.
400 OperationUnsupported.VpcRoutePropagationSource The operation on this VPC route propagation source is not supported. The operation on this VPC route propagation source is not supported.
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.