Server Load Balancer:Add a UDP listener

Prerequisites

• An NLB instance is created. For more information, see Create and manage an NLB instance.

• A server group is created. For more information, see Create and manage a server group.

Procedure

Create a UDP listener

1. Log on to the NLB console.

2. In the top navigation bar, select the region in which the NLB instance is deployed.

3. On the Instances page, find the NLB instance that you want to manage and use one of the following methods to open the listener configuration wizard:

   • Click Create Listener in the Actions column.

   • Click the ID of the NLB instance and click the Listener tab. On the Listener tab, click Create Listener above the listener list.

   • Click the instance ID. On the instance details page, click Create Listener in the wizard.

   • Click the instance ID. In the upper-right corner of the instance details page, click Create Listener.

4. In the Configure Listener step, configure the following parameters and click Next.

   Parameter	Procedure
   Quick Create Listener	Select a listener protocol. In this example, UDP is selected.
   Listen by Port Range	Specify whether to enable the listener to listen by port range. If you enable this feature, the NLB instance listens on all ports in the specified listener port range, and redirects requests destined for the ports to the backend servers. Note You must enable the all-port forwarding feature for server groups that you want to add to listeners that listen by port range.
   Listener Port Range	If you enable the listener to listen by port range, specify the first port and the last port to define the listener port range. Important The listener port range cannot be modified after the listener is created.
   Listener Port	Specify a port on which the NLB instance listens. The NLB instance uses the port to receive requests and forward the requests to backend servers. You can select a common port, or enter a port number. Valid values: 1 to 65535. Note If Listen by Port Range is enabled, you do not need to specify this parameter. For more information about how to configure listener ports for the same NLB instance, see Port settings.
   Listener Name	Enter a name for the listener.
   Tag	Configure the Tag Key and Tag Value parameters to add a tag. You can add one or more tags. After you specify tags, you can filter listeners by tag on the Listener tab.
   Advanced Settings	Click Modify to configure the advanced settings.
   Idle Connection Timeout Period	Specify a timeout period for idle UDP connections. If no request is received within the timeout period, NLB closes the current connection. When a request is received, NLB establishes a new connection.
   Limit on New Connections	Specify whether to limit the number of new connections.
   Maximum New Connections per Second	If you turn on Limit on New Connections, you must specify the maximum number of new connections per second that the listener can handle in each zone. Each zone provides a virtual IP address (VIP). Important This value applies only to the current listener. Connections to other listeners are not affected. To view the throttling values of other listeners, check the configurations of the listeners.
   Enable Proxy Protocol	Specify whether to enable Proxy Protocol. After Proxy Protocol is enabled, client IP addresses are passed to backend servers. For more information, see Enable NLB to preserve client IP addresses. Important The Proxy protocol takes effect only if it is enabled on both the proxy server and backend server. If the backend server cannot parse Proxy protocol headers but the Proxy protocol is enabled, parsing errors may arise on the backend server and compromise service availability.

5. In the Select Server Group step, select Server Type or IP, select a server group, view the backend servers, and then click Next.

6. In the Configuration Review step, confirm the configurations and click Submit.

Create a UDP listener (quick configuration)

If you select this method, you only need to specify a listener protocol, a listener port, and a server group.

1. In the left-side navigation pane, choose NLB > Instances.

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

3. Click the Listener tab. On the Listener tab, click Quick Create Listener.

4. In the Quick Create Listener dialog box, configure the parameters and click OK. The following table describes the parameters.

   Parameter	Procedure
   Quick Create Listener	Select a listener protocol. In this example, UDP is selected.
   Listener Port	Specify the frontend port that is used to receive requests and forward them to backend servers. You can select a common port, or enter a port number. Valid values: 1 to 65535.
   Server Group	Set Server Type or IP, and select a server group based on the specified server type or IP address.

References

• CreateListener: creates a TCP, UDP, or TCP/SSL listener for an NLB instance.

• DeleteListener: deletes a listener from an NLB instance.

• ListListeners: queries the listeners added to an NLB instance.

• UpdateListenerAttribute: updates the configuration of an NLB listener.

• StartListener: enables an NLB listener.

• StopListener: disables a listener for an NLB instance.

• GetListenerAttribute: queries the details about an NLB listener.

• GetListenerHealthStatus: queries the health status of an NLB listener.