Question 6

DNS functions at the Application layer of the OSI model.

DNS operates at the Application layer, which is responsible for providing network services directly to end-user applications. It facilitates the translation of human-readable domain names to machine-readable IP addresses.

A) Network layer

The Network layer is primarily concerned with the routing of data packets between devices across multiple networks. While it plays a crucial role in establishing the path data takes, it does not handle the translation of domain names, which is the primary function of DNS.

B) Presentation layer

The Presentation layer is responsible for data translation, encryption, and compression, preparing data for the Application layer. However, it does not perform any functions related to DNS, which is focused on resolving domain names to IP addresses.

C) Application layer

The Application layer is where DNS operates, as it directly interacts with user applications to provide network services. This layer enables users to utilize domain names without needing to understand the underlying IP addresses, highlighting its essential role in internet navigation.

D) Session layer

The Session layer manages sessions between applications, establishing and maintaining connections. While it is vital for communication between applications, it does not involve the name resolution process that DNS performs.

Conclusion

The correct answer is C, as DNS operates at the Application layer, providing essential services for name resolution that facilitate user access to websites. Options A, B, and D fail to capture the specific function of DNS, which is not related to routing, data formatting, or session management, further confirming that the Application layer is the appropriate context for DNS operations.