What option is used to add a DNS server on the DHCP server?

The correct answer is related to the specific configuration of parameters in DHCP (Dynamic Host Configuration Protocol). The option used to add a DNS server to a DHCP server is designated by the option code for DNS servers, which is 006. When a DHCP server is configured, it can provide a wide range of information to clients, including not only the IP addresses but also critical network configurations.

The option labeled as 006 DNS Servers allows the DHCP server to convey the IP addresses of the DNS servers that the clients should use to resolve domain names into IP addresses. This is essential because it helps ensure that client machines can navigate the network and access the Internet effectively by translating human-friendly domain names into machine-readable IP addresses.

By specifying multiple DNS servers in option 006, organizations can enhance redundancy and reliability, allowing clients to reach at least one functioning DNS server even if one fails, promoting seamless network operations.