1.2.9 Lesson Review

What is a Protocol Data Unit (PDU)?

A chunk of data with protocol-specific headers added at each OSI layer

Which of the following are layers of the OSI reference model? (Select three.)

Application layer Session Layer Presentation Layer

Match each networking function or device on the left with its associated OSI model layer on the right.

Application layer: HTTP Presentation layer: Translates Data Session layer: Session ID number Transport layer: Port number Network layer: Router Data Link Layer: Switch

When the Data Link layer performs encapsulation, it adds control information to the payload in the form of header fields. Which of the following are header fields added by the Data Link layer during encapsulation? (Select three.)

Destination hardware address Checksum for basic error checking Source hardware address

Which of the following functions are performed by the OSI Transport layer? (Select three.)

End to end flow control reliable message delivery Data segmentation and reassembly

A network engineer is designing a network in various offices to create multiple broadcast domains. Each has its own Virtual Local Area Network (VLAN). When configuring these multiple broadcast domains on the switch, the switch will be operating at what layer of the OSI model?

Layer 2 Data Link Layer

A security engineer configures software-based port security on a hardware firewall. Which OSI model layer identifies the application ports to configure?

Layer 4

An engineer uses a type of network adapter to connect a fiber link to a router. The transceiver fits into an optical interface on a layer 3 Ethernet router. Of the choices, which layer 1 implementation does the engineer utilize?

Media Converter

A communications engineer notices that every time it rains the signal becomes very degraded. Which layer of the OSI model is the engineer most likely troubleshooting?

Physical

Which of the following devices operate at the Data Link layer of the OSI model? (Select three.)

Switches Network Interface Cards Bridges

What role does the Presentation layer (layer 6) of the OSI model play in terms of data compression and encryption?

The Presentation layer supports data compression and encryption to prepare data for network transmission.

Which of the following statements accurately describes the function of the Session layer (layer 5) in the OSI model?

The Session layer administers the process of establishing, managing, and terminating a dialog between client and server.

In the OSI model, what is the primary function of the Network layer?

The primary function of the Network layer is to move data around an internetwork using logical network and host IDs.

What is the primary purpose of data encapsulation in network protocols?

To add additional data headers for routing and delivery

What is the role of an Access Control List (ACL) at Layer 3 (Network layer) of the OSI model?

To filter network traffic by permitting or blocking packets based on IP addresses and other criteria