Cloud Enterprise Network:Create and manage a multicast network

Step 1: Prepare the environment

1. Create an Enterprise Edition transit router in the region where you want to create a multicast network and enable the multicast feature for the transit router. For more information, see Create a transit router instance.

   Important

   • Multicast is supported only by Enterprise Edition transit routers in the following regions: China (Hangzhou), China (Shanghai), China (Beijing), China (Ulanqab), China (Shenzhen), China (Chengdu), China (Hohhot), China (Hong Kong), Japan (Tokyo), Singapore, Germany (Frankfurt), UK (London), US (Virginia), US (Silicon Valley), and SAU (Riyadh - Partner Region).

   • You can enable the multicast feature only when you create an Enterprise Edition transit router. If you have an Enterprise Edition transit router in a region that supports multicast but you cannot use the multicast feature, you must delete the transit router and create a new one. For more information about how to delete an Enterprise Edition transit router, see Delete a transit router instance.

2. Connect the VPCs where you want to create the multicast network using an Enterprise Edition transit router. For more information, see Connect on-premises data centers to VPCs or Create a cross-account VPC-to-VPC connection.

Step 2: Create a multicast domain

Create a multicast domain and associate it with one or more vSwitches to define the scope of the multicast network. Only resources in the vSwitches associated with the multicast domain can send and receive multicast traffic.

1. Log on to the CEN console.

2. On the Instances page, click the ID of the CEN instance that you want to manage.

3. On the Basic Information > TransitRouter tab, click the instance ID.

4. On the TransitRouter instance details page, click the Multicast tab and then click Create Multicast Domain.

5. In the Create Multicast Domain dialog box, set the following parameters and click OK.

   Configuration item	Description
   Transit Router	The ID of the transit router in the current region is displayed.
   Multicast Domain Name	Enter a name for the multicast domain.
   Multicast Domain Feature	Specifies whether to enable the Internet Group Management Protocol (IGMP) feature for the multicast domain. After you enable this feature, hosts can dynamically join or leave a multicast group using IGMP. This feature is enabled by default. In a scenario where a multicast network is created in static mode, you can disable this feature. In a scenario where a multicast network is created in IGMP mode, you must enable this feature. After the IGMP feature is enabled, it cannot be disabled.
   VPC	Select the VPC to associate with the multicast domain.
   vSwitch	Select the vSwitch to associate with the multicast domain.
   Description	Enter a description for the multicast domain.
   Tag	Configure tags for the multicast domain. Tag Key: The tag key can be up to 64 characters in length. It cannot be an empty string or start with acs: or aliyun or contain http:// or https://. Tag Value: The tag value can be an empty string with a maximum length of 128 characters. It cannot start with acs: or aliyun or contain http:// or https://. You can add multiple tags to a multicast domain. For more information, see Tags.

   To attach vSwitches in multiple VPCs, see the Attach a vSwitch operation in More operations.

Step 3: Create a multicast source

After you create a multicast domain, create a multicast source in the multicast domain and specify a multicast group for the multicast source. After the multicast source is created, it sends multicast traffic to the multicast group. The multicast members in the multicast group can then receive the multicast traffic from the multicast source.

1. Log on to the CEN console.

2. On the Instances page, click the ID of the CEN instance that you want to manage.

3. On the Basic Information > TransitRouter tab, click the instance ID.

4. On the Transit Router instance details page, click the Multicast tab, and then click the multicast domain ID in the left-side section of the Multicast tab.

5. In the Multicast Domain Details section, on the Multicast Groups tab, click Add Multicast Source.

6. On the Add Multicast Source page, set the following parameters and click OK.

   Configuration item		Description
   Basic Information	Transit Router	The ID of the transit router in the current region is displayed.
   	Multicast Domain	The ID of the selected multicast domain is displayed.
   Multicast Group Info	Multicast Group	Select the multicast group to which the multicast source belongs. Valid values: Create Multicast Group: If no multicast group is created in the selected multicast domain, you can select this option and enter an IP address. The system automatically creates a multicast group. Note After a multicast group is created, you cannot change its IP address. Select Multicast Group: If a multicast group already exists in the current multicast domain, you can select this option to create a multicast source in the specified multicast group.
   	New Multicast Group IP	Enter the IP address of the new multicast group. The value must be in the range of 224.0.0.128 to 239.255.255.254. Important The IP addresses from 224.0.0.0 to 224.0.0.127 are system reserved IP addresses and cannot be used as multicast group IP addresses. Each multicast group is identified by a multicast IP address. You need to configure this parameter only when you select Create Multicast Group.
   	Multicast Group	Select a multicast group from the list of created multicast groups. After you select a group, the new multicast source belongs to this multicast group. This parameter is required only if you select Select Multicast Group.
   Multicast Source Information	Resource Type	Select the type of multicast source. Default value: ENI. Currently, only elastic network interfaces (ENIs) that are attached to ECS instances can be used as multicast sources. The system uses the primary private IP address of the ENI to send multicast traffic to the multicast group. You can specify up to five ENIs as multicast sources at a time.
   	vSwitch	Select the vSwitch where the multicast source is located.
   	ENI	Select an ENI to use as the multicast source. If you select Add as Multicast Member to the right of the drop-down list, the elastic network interface is also added to the multicast group as a multicast member after the creation is complete.

Step 4: Create a multicast member

If you did not specify a multicast member when you created the multicast source, you can follow these steps to specify one. A resource must be a multicast member to receive multicast traffic. Multicast members receive traffic only from the multicast group to which they belong.

1. Log on to the CEN console.

2. On the Instances page, click the ID of the CEN instance that you want to manage.

3. On the Basic Information > TransitRouter tab, click the instance ID.

4. On the Transit Router instance details page, click the Multicast tab, and then click the multicast domain ID in the left-side section of the Multicast tab.

5. In the Multicast Domain Details section, on the Multicast Groups tab, click Add Group Member.

6. On the Add Multicast Member page, set the following parameters and click OK.

   Configuration item		Description
   Basic Information	Transit Router	The ID of the transit router in the current region is displayed.
   	Multicast Domain	The ID of the selected multicast domain is displayed.
   Multicast Group Info	Multicast Group	Select the multicast group to which the multicast member belongs. Valid values: Create Multicast Group: If no multicast group exists in the current multicast domain, select this option and enter the IP address for the new multicast group. The system automatically creates a multicast group. Note After a multicast group is created, you cannot change its IP address. Select Multicast Group: If multicast groups already exist in the current multicast domain, you can select this configuration item to create multicast members for a specified multicast group.
   	New Multicast Group IP	Enter the IP address of the new multicast group. The value must be in the range of 224.0.0.128 to 239.255.255.254. Important The IP addresses from 224.0.0.0 to 224.0.0.127 are system reserved IP addresses and cannot be used as multicast group IP addresses. Each multicast group is identified by a multicast IP address. This parameter is required only when you select Create Multicast Group.
   	Multicast Group	Select a multicast group from the list of created multicast groups. This parameter is required only if you select Select Multicast Group.
   Group Member Info	Resource Type	Select the resource type of the multicast member. Valid values: ENI (default value): Select an ENI in the vSwitch. Currently, only ENIs that are attached to ECS instances can be used as multicast members. The system uses the primary private IP address of the ENI to receive multicast traffic. You can click Add ENI to add multiple ENIs. Inter-region Multicast Domain: Select the multicast domain for the cross-region TransitRouter instance. If you select a multicast domain that belongs to a transit router in another region, the multicast members of the multicast group that has the same IP address in the inter-region multicast domain are used as the multicast members of the current multicast group. ExampleFor example, a multicast group A exists in multicast domain 1 in the China (Hangzhou) region. Another multicast group A exists in multicast domain 2 in the China (Shanghai) region. Both groups have the same multicast IP address, and the group in domain 2 already has members. To create a member for group A in domain 1, you can Select Multicast Domain as the resource type and select domain 2 in the China (Shanghai) region. After the operation is complete, the members of group A in domain 2 are also considered members of group A in domain 1 by default. This allows them to receive multicast traffic from group A in domain 1. Important Before you select Inter-region Multicast Domain, make sure that: An inter-region connection is created between the two regions where you want to transmit multicast traffic, and the networks are connected. The two regions have multicast groups with the same multicast IP address, and the multicast group in the peer region already has multicast members. The system supports adding multicast members across regions, but does not support adding multicast sources across regions. For scenarios where you add inter-region multicast members, if you have already added inter-region multicast members in the local multicast domain, you cannot add local multicast members of the same multicast group in the inter-region multicast domain. This means that for the same multicast group, you can add inter-region multicast members in only one of the multicast domains.
   	vSwitch	Select the vSwitch where the multicast member is located. This parameter is required only if you select ENI.
   	ENI	Select an ENI to use as the multicast member. This parameter is required only if you select ENI. If you select Inter-region Multicast Domain to the right of the dropdown list, the ENI will also be specified as a multicast source for the multicast group after creation is complete. You can specify up to five multicast members at a time. If you select resources from a VPC-connected instance that belongs to another account in an operation, you can specify one or more ENIs from only that VPC-connected instance as multicast members. You cannot specify ENIs from multiple cross-account VPC-connected instances as multicast members in the same operation.
   	Transit Router	Select the transit router instance in the peer region. This parameter is required only when you select Inter-region Multicast Domain.
   	Peer Multicast Domain	Select a multicast domain that belongs to the transit router instance in the peer region. You need to configure this parameter only if you select Inter-region Multicast Domain.