In network security, what does the term "DNS Tunneling" refer to?

The term "DNS Tunneling" refers specifically to a method for data exfiltration using DNS queries. This technique leverages the Domain Name System (DNS) protocol—typically used for translating domain names into IP addresses—to transmit data in a way that bypasses traditional security measures.

In this context, an attacker can embed data within DNS requests and responses, as DNS traffic is often allowed to pass through firewalls without much scrutiny. This allows them to secretly send and receive data over the network without detection, making DNS tunneling a popular vector for cyber threats.

While other options mention various network security practices, none of them describe the specific function of DNS tunneling. Techniques for preventing intrusion or features in firewalls focus on safeguarding the network rather than exfiltrating data. Similarly, algorithms for balancing server load deal with resource management rather than data security or exfiltration.