Exam 200-301 topic 1 question 331 discussion

The question specifically says LEARNING. A Static MAC is not learned

A. Wrong - MAC address learning is generally enabled by default on switches. B. Wrong - in this case the next step would be to replicate the original frame to the remaining ports (flood), in order to find the destination. C. Wrong - MAC learning on a switch (MAC table) is not used to populate the ARP table. MAC learning takes place at the layer 2 level of the OSI model, while the ARP table is related to layer 3, the IP protocol. The ARP table is populated by the host's response frame from the searched IP address destination (ARP reply). D. Correct - in MAC table learning, the addresses are learned by dynamically received frames, but it can also be learned statically, adding manually, when you want to force a destination for a specific host. Perhaps, in this case the static form can be considered a form of learning.

ARP is using to map layer 2 address to layer 3 address and the ARP table is not filled with CAM table. D is correct

When a switch receives a frame with a destination MAC address not in its table, it will flood the frame out all ports (except the one it came from). If no response is received back to update the MAC address table, the frame is ultimately dropped. So the best answer is B

Actually, I am starting to doubt whether these are real CCNA questions. They are full of logic errors, incorrect use of terms, misinterpreted textbook sentences. Could some of them are fake questions purposely released to the internet by Cisco to confuse learners? As a leader in the networking industry, Cisco cannot even find someone who has normal English literacy and normal intellectual level to create some questions that make sense to human readers?

Only C is talking about a FUNCTION. All the other options, whether true of false, are not a function.

A switch doesn't even have an arp table, Answer D is correct

D is the only correct statement (on its own). However, it seems like an incorrect answer to the question about MAC *learning*.

it is D

D answer is correct.

Arp is not a laser 2 protocol Answer is D because static mac addresses are learned by manual input

D is correct a static MAC address is considered as MAC learning as well. also read this https://www.cisco.com/c/en/us/td/docs/optical/cpt/r_972/cpt95_configuration/cpt93_configuration_chapter_01100.pdf (page 12)

MAC learning on a switch involves dynamically building and maintaining a MAC address table (CAM table) that maps MAC addresses to the ports on which they are learned. This table is used to make forwarding decisions based on destination MAC addresses. If a frame is received for a destination MAC address that is not listed in the MAC address table, the switch will flood the frame out of all ports except the port on which the frame was received. This helps prevent unnecessary flooding of frames within the network

Let’s say that host A wants to communicate with host B for the first time. Host A knows the IP address of host B, but since this is the first time the two hosts communicate, the hardware (MAC) addresses are not known. Host A uses the ARP process to find out the MAC address of host B. The switch forwards the ARP request out all ports except the port the host A is connected to. Host B receives the ARP request and responds with its MAC address. Host B also learns the MAC address of host A (because host A sent its MAC address in the ARP request). Host C receives the ARP request, but doesn’t respond since the IP address listed in the request is not its own. https://study-ccna.com/how-switches-work/

C is correct. Address Resolution Protocol (ARP) is a layer 2 protocol used to map MAC addresses to IP addresses. ARP requests are broadcast and sent on the shared local subnet. That is done to update (populate) each ARP table between source and destination. D is incorrect, beacause when you add a static MAC address, it will be (automatically) added to the MAC table.

The question is asking what is a "function", answer should be "To built CAM table, so that the switch makes an independent forwarding decision based on it. Unless the question is "How a Switch learns the MAC addresses?" then the answer is D.

It´s D. MAC table is not used to populate ARP table.