200-301 · Question #1346
How does frame switching function on a switch?
The correct answer is A. floods unknown destinations to all ports except the receiving port. When a switch receives a frame destined for an unknown MAC address, it floods the frame to all its ports, excluding the port it was received on, to ensure the frame reaches its intended recipient.
Question
Options
- Afloods unknown destinations to all ports except the receiving port
- Bbuffers and forwards frames with less than 5 CRCs
- Cforwards frames to a neighbor port using CDP
- Dsends frames with unknown destinations to a multicast group
How the community answered
(33 responses)- A91% (30)
- B6% (2)
- C3% (1)
Why each option
When a switch receives a frame destined for an unknown MAC address, it floods the frame to all its ports, excluding the port it was received on, to ensure the frame reaches its intended recipient.
A fundamental function of a Layer 2 switch is to flood frames with an unknown destination MAC address to all ports within the same VLAN, except for the port on which the frame was originally received. This ensures that the frame reaches the intended recipient if it exists within the connected network segment, and allows the switch to learn the recipient's MAC address in the process when a reply is received.
The number of CRCs is not a standard forwarding criterion; frames with valid CRCs are forwarded, while corrupted ones are discarded.
CDP (Cisco Discovery Protocol) is a Layer 2 protocol for discovering neighbor devices and their capabilities, not for forwarding user data frames.
Frames with unknown unicast destinations are flooded to all ports (except ingress), not specifically sent to a multicast group.
Concept tested: Switch frame forwarding (unknown unicast)
Source: https://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-series-switches/10570-41.html
Topics
Community Discussion
No community discussion yet for this question.