Examice

Exam GPEN All QuestionsBrowse all questions from this exam

Question 39

Given the following Scapy information, how is default Layer 2 information derived?

The default layer 2 information is contained in a local scapy.cfg configuration fileon the local system.

If not explicitly defined, the Ether type field value Is created using the hex value ofthe destination port, in this case 80

If not explicitly defined, pseudo-random values are generated for the Layer 2 defaultinformation.

Scapy relies on the underlying operating system to construct Layer 2 information touse as default.

Correct Answer: D

Scapy relies on the underlying operating system to construct Layer 2 information to use as default. This means that if a Layer 2 field such as MAC address is not explicitly defined, Scapy will use the MAC address of the network interface card (NIC) of the system it is running on. The provided Scapy information reflects constructing packets where Ether (Layer 2) and IP (Layer 3) headers are specified without defining all fields, confirming the usage of defaults from the operating system.

Discussion

devnullOption: D

The correct answer is D. If you actually try it, you can confirm that the MAC address adopted by scapy corresponds to the MAC address of the actual NIC.