Step 1:
Enable dns service on the inside interface
ciscoasa(config)# dns domain-lookup inside
Enable dns service on the inside interface
ciscoasa(config)# dns domain-lookup inside
Step 2:
Define dns servers:
ciscoasa(config)# dns name-server 4.2.2.2 4.2.2.3
Define dns servers:
ciscoasa(config)# dns name-server 4.2.2.2 4.2.2.3