You can use DHCP services to get the DNS server information for the target workload to use, or specify the IP address of one or multiple DNS servers to use.
For Windows workloads, select the Use DHCP to get name servers check box to acquire the DNS server information from the DHCP server in the associated network. If you specify a static IP address, deselect the check box, then manual specify the DNS server information in the DNS Servers field.
For Linux workloads, deselect the Use DHCP to get name servers check box, then manually specify the DNS server information in the DNS Servers field.