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210-255 · Question #110

Which two useful pieces of information can be collected from the IPv4 protocol header? (Choose two.)

The correct answer is B. source IP address of the packet E. destination IP address of the packet. The IPv4 header contains source and destination IP addresses at the network layer, while port information belongs to the transport layer headers (TCP/UDP) and is not present in the IPv4 header itself.

Network Intrusion Analysis

Question

Which two useful pieces of information can be collected from the IPv4 protocol header? (Choose two.)

Options

  • AUDP port which the traffic is destined
  • Bsource IP address of the packet
  • CUDP port from which the traffic is sourced
  • DTCP port from which the traffic was source
  • Edestination IP address of the packet

How the community answered

(49 responses)
  • A
    2% (1)
  • B
    92% (45)
  • C
    2% (1)
  • D
    4% (2)

Why each option

The IPv4 header contains source and destination IP addresses at the network layer, while port information belongs to the transport layer headers (TCP/UDP) and is not present in the IPv4 header itself.

AUDP port which the traffic is destined

UDP destination port is a field in the UDP header at Layer 4, not in the IPv4 header at Layer 3.

Bsource IP address of the packetCorrect

The source IP address is a defined 32-bit field in the IPv4 header (RFC 791), identifying the originating host of the packet. Together with the destination IP address, these are the two network-layer identifiers carried in every IPv4 packet header.

CUDP port from which the traffic is sourced

UDP source port is a field in the UDP header at Layer 4, not in the IPv4 header at Layer 3.

DTCP port from which the traffic was source

TCP source port is a field in the TCP header at Layer 4, not in the IPv4 header at Layer 3.

Edestination IP address of the packetCorrect

The destination IP address is a defined 32-bit field in the IPv4 header (RFC 791), identifying the intended recipient of the packet and used by routers to make forwarding decisions.

Concept tested: IPv4 header field identification

Source: https://www.rfc-editor.org/rfc/rfc791

Topics

#IPv4 header#packet analysis#IP addressing

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