Can a iRule instruct the LB to stop its DNS service

Hi

We have two DCs both have one LB and they are configured in active standby. If the link between the LBs is broken they wil both become active and start answering DNS requests however only one DC will acturally have a backend service that will be operational. Is it possible to configure a iRule that monitors my backend service and will instruct the LB to stop answering DNS requests if the backend server is not operational?

Kind regards,

hgru