How does a Layer 2 switch determine how to forward frames?

How does a Layer 2 switch determine how to forward frames?

• A. Frame forwarding decisions are based on IP address and routing tables
• B. Frame forwarding decisions are based on MAC address and port mappings in the CAM table
• C. Frame forwarding decisions are based on VLAN tags alone
• D. Frame forwarding decisions are determined by the speed of each port

Answer: (B)

A Layer 2 switch determines how to forward frames primarily by using MAC addresses and the mappings found in its Content Addressable Memory (CAM) table. When a frame arrives at a switch, the device checks the source MAC address of the incoming frame and learns which port it came from. This information is added to the CAM table, creating a mapping between the MAC address and the specific port. When the switch needs to forward a frame, it looks up the destination MAC address in the CAM table to determine the appropriate port to send the frame out of. If the destination MAC address is found in the CAM table, the switch forwards the frame only to the associated port, which minimizes unnecessary traffic on other ports. If the MAC address is not found, the switch will flood the frame to all ports except the one it originated from, to ensure that it reaches the intended recipient. This process is fundamental to the operation of Layer 2 switches, which function at the data link layer of the OSI model, making forwarding decisions based solely on MAC addresses, rather than relying on IP addresses or other criteria.

A Layer 2 switch determines how to forward frames primarily by using MAC addresses and the mappings found in its Content Addressable Memory (CAM) table. When a frame arrives at a switch, the device checks the source MAC address of the incoming frame and learns which port it came from. This information is added to the CAM table, creating a mapping between the MAC address and the specific port.

When the switch needs to forward a frame, it looks up the destination MAC address in the CAM table to determine the appropriate port to send the frame out of. If the destination MAC address is found in the CAM table, the switch forwards the frame only to the associated port, which minimizes unnecessary traffic on other ports. If the MAC address is not found, the switch will flood the frame to all ports except the one it originated from, to ensure that it reaches the intended recipient.

This process is fundamental to the operation of Layer 2 switches, which function at the data link layer of the OSI model, making forwarding decisions based solely on MAC addresses, rather than relying on IP addresses or other criteria.