System Administrator 2026 — Test 51

Correct Answer: C. C. Ah; esp
Explanation: AH ensures that there is no retransmission of data from an unauthorized source, and protects against data tampering. ESP provides with content protection and ensures that there is integrity and confidentiality for the message.

Correct Answer: A. A. Network
Explanation: IPSec is a set of protocols used to provide authentication, data integrity and confidentiality between two machines in an IP network. In the TCP/IP model, it provides security at the IP layer i.e. the network layer.

Correct Answer: D. D. Error control
Explanation: The ESP provides data confidentiality, integrity and authentication. It provides confidentiality through encryption. ESP can operate in two modes, transport mode and tunnel mode.

Correct Answer: B. B. Integrity
Explanation: Integrity means that computer system assets can be modified only by authorized parities. Confidentiality means that the assets can only be accessed by authorized parties. Availability refers to the accessibility of the resource to the authorized parties. Authenticity means that the asset is not unethically changed.

Correct Answer: A. A. Confidentiality
Explanation: Confidentiality means that the assets can only be accessed by authorized parties. Integrity means that computer system assets can be modified only by authorized parities. Availability refers to the accessibility of the resource to the authorized parties. Authenticity means that the asset is not unethically changed.

Correct Answer: A. A. Nsa
Explanation: The NSA is primarily responsible for military encryption systems. The NSA designs evaluates, and implements encryption systems for the military and government agencies with high security needs.

Correct Answer: D. D. Virtual circuit network is implemented in application layer
Explanation: Virtual circuit network is normally implemented in data link layer. It is a combination of circuit-switched network and datagram network which are implemented in the physical layer and network layer respectively.

Correct Answer: A. A. Global address
Explanation: Global address is a network address that is unique internationally and is used as a common address by all the users of the network. It is used to create a virtual circuit identifier.

Correct Answer: B. B. Virtual circuit identifier
Explanation: A virtual circuit identifier is a type of numeric identifying address that is used to distinguish between different virtual circuits in a circuit-switched network. It is used for data transfer and has a switch scope.

Correct Answer: C. C. Termination phase
Explanation: There are three phases in a virtual circuit network: setup, data transfer and teardown phase. There is no termination phase in it.