200-301 · Question #358
How does a switch process a frame received on Fa0/1 with the destination MAC address of 0e38.7363.657b when the table is missing the address?
The correct answer is C. It floods the frame to all interfaces except Fa0/1.. When a switch receives a frame with a destination MAC address not found in its MAC address table, it floods the frame out of all interfaces except the one it was received on.
Question
How does a switch process a frame received on Fa0/1 with the destination MAC address of 0e38.7363.657b when the table is missing the address?
Options
- Alt drops the frame immediately.
- BIt forwards the frame back out of interface Fa0/1.
- CIt floods the frame to all interfaces except Fa0/1.
- DIt holds the frame until the MAC address timer expires and then drops the frame.
How the community answered
(39 responses)- A3% (1)
- C92% (36)
- D5% (2)
Why each option
When a switch receives a frame with a destination MAC address not found in its MAC address table, it floods the frame out of all interfaces except the one it was received on.
A switch does not drop frames simply because the destination MAC address is unknown; it floods them to ensure delivery.
If a switch does not have an entry for a destination MAC address in its MAC address table, it floods the unknown unicast frame to all ports in the same VLAN, excluding the ingress port, in an attempt to reach the destination device and learn its MAC address.
Concept tested: Switch MAC address table learning and unknown unicast flooding
Source: https://www.cisco.com/c/en/us/support/docs/lan-switching/ethernet-switching/10574-5.html
Topics
Community Discussion
No community discussion yet for this question.