A listener is a specialized virtual server that passively checks for DNS packets on port 53 and the IP address you assign to the listener. When a DNS query is sent to the IP address of the listener, BIG-IP GTM either handles the request locally or forwards the request to the appropriate resource.

1. On the Main tab, click DNS > Delivery > Load Balancing > Pools or Local Traffic > Pools. The Pool List screen opens.
2. Click Create. The New Pool screen opens.
3. In the Name field, type a unique name for the pool.
4. For the Health Monitors setting, from the Available list, select the custom DNS monitor you created, and click << to move the monitor to the Active list.
5. Using the New Members setting, add each resource that you want to include in the pool:
   1. Type an IP address in the Address field.
   2. Type a port number in the Service Port field, or select a service name from the list.
   3. To specify a priority group, type a priority number in the Priority Group Activation field.
   4. Click Add.
6. Click Finished.

1. On the Main tab, click DNS > Delivery > Listeners. The Listeners List screen opens.
2. Click Create. The Listeners properties screen opens.
3. In the Name field, type a unique name for the listener.
4. For the Destination setting, in the Address field, type an IPv4 address on which GTM listens for network traffic.
5. From the Listener list, select Advanced.
6. For the Address Translation setting, select the Enabled check box.
7. In the Service area, from the Protocol list, select UDP.
8. From the Default Pool list, select the pool to which this listener forwards DNS queries.
9. Click Finished.