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GSEC · Question #309

What is it called when an OSI layer adds a new header to a packet?

The correct answer is B. Encapsulation. Encapsulation is the OSI process where each layer prepends its own protocol header to the data unit it receives from the layer above as data travels down the stack toward the physical medium.

Networking and Core Concepts

Question

What is it called when an OSI layer adds a new header to a packet?

Options

  • ASwitching
  • BEncapsulation
  • Cfragmentation
  • DRouting

How the community answered

(52 responses)
  • A
    8% (4)
  • B
    77% (40)
  • C
    12% (6)
  • D
    4% (2)

Why each option

Encapsulation is the OSI process where each layer prepends its own protocol header to the data unit it receives from the layer above as data travels down the stack toward the physical medium.

ASwitching

Switching is a Layer 2 forwarding function that moves frames between ports based on MAC addresses and has no role in adding protocol headers.

BEncapsulationCorrect

Encapsulation occurs as data passes down the OSI model - each layer wraps the incoming data unit with its own header (and sometimes trailer), creating a new protocol data unit. For example, the Transport layer adds a TCP/UDP header, the Network layer adds an IP header, and the Data Link layer adds a frame header, each 'encapsulating' the payload from the layer above.

Cfragmentation

Fragmentation is the process of splitting a packet into smaller pieces to meet a network's maximum transmission unit (MTU) requirement, not a header-addition process.

DRouting

Routing is a Layer 3 path-selection function that forwards packets toward their destination based on IP addresses, not a process of adding headers to packets.

Concept tested: OSI model encapsulation and protocol data units

Source: https://www.cloudflare.com/learning/network-layer/what-is-a-packet/

Topics

#OSI model#encapsulation#packet headers#networking fundamentals

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