After a GWLB instance is created, a listener is automatically generated without additional configuration. The GWLB instance monitors all IP packets on all ports and forwards the traffic to a specified target group.
Only one listener is available for a GWLB instance and additional listeners cannot be added.
Binding a Target Group
1. On the Listener Management page, click Bind Target Group.
2. In the pop-up box, choose an appropriate target group.
3. After completing the selection, click OK to complete the target group binding.
Reference