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Cloud Enterprise Network:CreateTransitRouter

Last Updated:Jul 15, 2026

Creates an Enterprise Edition transit router instance.

Operation description

  • You can call the CreateTransitRouter operation to create an Enterprise Edition transit router instance. Enterprise Edition transit routers are available only in some regions. For more information about regions, see What is Cloud Enterprise Network?.

  • CreateTransitRouter is an asynchronous operation. After you send a request, the system returns an Enterprise Edition transit router instance ID but the instance is not yet created. The creation task is still running in the background. You can call the ListTransitRouters operation to query the status of the Enterprise Edition transit router instance.
    • If the Enterprise Edition transit router instance is in the Creating state, the instance is being created. In this state, you can only query the instance and cannot perform other operations on it.

    • If the Enterprise Edition transit router instance is in the Active state, the instance is created.

  • Only one transit router instance can be created in each region within a Cloud Enterprise Network (CEN) instance.

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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:CreateTransitRouter

create

CenInstance

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

TransitRouter

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

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 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 request.

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

CenId

string

Yes

The instance ID of the CEN instance.

cen-j3jzhw1zpau2km****

RegionId

string

Yes

The region ID of the Enterprise Edition transit router instance.

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

cn-zhangjiakou

TransitRouterName

string

No

The name of the Enterprise Edition transit router instance.

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

testname

TransitRouterDescription

string

No

The description of the Enterprise Edition transit router instance.

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

testdesc

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 Enterprise Edition transit router instance after the request passes the check.

  • true: Sends a check request without creating the Enterprise Edition transit router instance. The system checks the required parameters, request format, and other conditions. If the check fails, the corresponding error is returned. If the check passes, the error code DryRunOperation is returned.

false

SupportMulticast

boolean

No

Specifies whether to enable the multicast feature for the Enterprise Edition transit router. Valid values:

  • false (default): Disabled.

  • true: Enabled.

Only Enterprise Edition transit routers in some regions support the multicast feature. You can call the ListTransitRouterAvailableResource operation to query the regions that support the multicast feature.

false

TransitRouterCidrList

array<object>

No

The list of transit router CIDR blocks.

object

No

The list of transit router CIDR blocks.

You can add up to five transit router CIDR blocks at a time. For more information about transit router CIDR blocks, see Transit router CIDR blocks.

Note

Only Enterprise Edition transit routers support CIDR blocks.

Cidr

string

No

The transit router CIDR block.

192.168.10.0/24

Name

string

No

The name of the transit router CIDR block.

The name must be 1 to 128 characters in length.

nametest

Description

string

No

The description of the transit router CIDR block.

The description must be 1 to 256 characters in length.

desctest

PublishCidrRoute

boolean

No

Specifies whether to allow the system to automatically add a route for the transit router CIDR block to the transit router route table.

  • true (default): Allowed.

    If you select this option, after you create a VPN connection of the private gateway type and create a route learning relationship for the VPN connection, the system automatically adds a route entry to the transit router route table that has a route learning relationship with the VPN connection:

    A blackhole route whose destination CIDR block is the transit router CIDR block from which gateway IP addresses are allocated for the IPsec connection.

    The blackhole route is propagated only to the route tables of virtual border router (VBR) instances associated with the transit router.

  • false: Not allowed.

true

Tag

array<object>

No

The tag information.

object

No

The tag information.

You can specify up to 20 tags at a time.

Key

string

No

The tag key of the resource.

Once specified, the tag key cannot be an empty string. The tag key can be up to 64 characters in length, and cannot start with aliyun or acs:, or 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 empty or up to 128 characters in length, and cannot start with aliyun or acs:, or contain http:// or https://.

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

TagValue

Response elements

Element

Type

Description

Example

object

The response parameters.

TransitRouterId

string

The ID of the Enterprise Edition transit router instance.

tr-uf6llz2286805i44g****

RequestId

string

The request ID.

404DA7EC-F495-44B5-B543-6EDCDF90F3D1

Examples

Success response

JSON format

{
  "TransitRouterId": "tr-uf6llz2286805i44g****",
  "RequestId": "404DA7EC-F495-44B5-B543-6EDCDF90F3D1"
}

Error codes

HTTP status code

Error code

Error message

Description

400 OperationUnsupported.RegionId The specified Region is not supported. The error message returned because this operation is not supported in the specified region.
400 InstanceExist.TransitRouterInstance The instance already exists. The error message returned because a transit router with the same ID already exists in the current region. Transit router IDs in the same region must be unique.
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 OperationUnsupported.SupportMulticast The multicast is not supported in the specified region. The error message returned because multicast is not supported in the specified region.
400 OperationUnsupported.CenFullLevel CEN full level does not support TransitRouter.
400 IllegalParam.Cidr Cidr is illegal. The error message returned because the specified CIDR block is invalid.
400 Illegal.TrType The TransitRouter type is illegal. The error message returned because the specified type of transit router does not support this operation.
400 OperationUnsupported.TransitRouterCidrList The TransitRouterCidrList is not support in the specified Region. The error message returned because this operation is not supported in the specified region.
400 OperationFailed.CidrConflict Operation is invalid because the cidr conflict. The error message returned because the specified CIDR block conflicts with another one.
400 IllegalParam.Region The specified region is invalid.
400 OverLappingExist.Cidr The cidr overlapping exist. The error message returned because CIDR overlapping is already enabled.
400 IllegalParam.ServiceMode The specified ServiceMode is invalid. The error message returned because the specified service mode is invalid.
400 ParamExclusive.ServiceModeAndSupportMulticast ServiceMode and SupportMulticast is mutually exclusive. The error message returned because transit routers in the current mode do not support multicast.
400 ParamExclusive.ServiceModeAndTransitRouterCidrList ServiceMode and TransitRouterCidrList is mutually exclusive. The error message returned because transit routers in the current mode do not support CIDR blocks.
400 OperationUnsupported.Tag The Tag is not supported in the specified region. The error message returned because transit routers in the current region do not support tags.
400 IllegalParam.SupportMulticast Basic Transit router is not support multicast. The error message returned because Basic Edition transit routers do not support multicast.
400 ParamExclusive.BasicAndPrimaryStandby Basic and PrimaryStandby is mutually exclusive. The error message returned because Basic Edition transit routers do not support the PrimaryStandby mode.
400 ParamExclusive.BasicAndMultiPrimary Basic and MultiPrimary is mutually exclusive. The error message returned because Basic Edition transit routers do not support the MultiPrimary mode.
400 IllegalParam.RegionId The Specified Parameter RegionId is illegal. The region specified in the parameter is invalid.
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 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 IllegalParam.TagValue The tag values are not valid. The error message returned because the specified tag value is invalid.
400 IllegalParam.TagKey The tag keys are not valid. The error message returned because the specified tag key is invalid.
400 InvalidParameter.TagValue The specified parameter TagValue is invalid. The input parameter Tag Value is invalid.

See Error Codes for a complete list.

Release notes

See Release Notes for a complete list.