Which statement is correct about how a Layer 2 switch determines how to forward frames?
- Only frames with a broadcast destination address are forwarded out all active switch ports.
- Frame forwarding decisions are based on MAC address and port mappings in the CAM table.
- Cut-through frame forwarding ensures that invalid frames are always dropped.
- Unicast frames are always forwarded regardless of the destination MAC address.
Explanation:
Cut-through frame forwarding reads up to only the first 22 bytes of a frame, which excludes the frame check sequence and thus invalid frames may be forwarded. In addition to broadcast frames, frames with a destination MAC address that is not in the CAM are also flooded out all active ports. Unicast frames are not always forwarded. Received frames with a destination MAC address that is associated with the switch port on which it is received are not forwarded because the destination exists on the network segment connected to that port. |