Advantages of Layer 2 Ethernet Switches Over Hubs

BC

The correct answers are B. filtering frames based on MAC addresses and C. allowing simultaneous frame transmissions.

Explanation: Ethernet switches operate at Layer 2 of the OSI model and provide several advantages over hubs, which are also Layer 1 devices.

Advantages of Layer 2 Ethernet switches over hubs:

B. Filtering frames based on MAC addresses: Ethernet switches learn which devices are connected to which ports by examining the source MAC address of incoming frames. By maintaining a table of MAC address-to-port mappings, switches can forward frames only to the ports where the destination devices are located. This reduces network congestion by limiting the number of unnecessary broadcasts and allows for greater network security by preventing unauthorized access.

C. Allowing simultaneous frame transmissions: Hubs operate in half-duplex mode, which means that devices connected to a hub must take turns transmitting frames. This can lead to collisions, which degrade network performance. Ethernet switches operate in full-duplex mode, which allows devices to transmit and receive frames simultaneously without collisions. This increases network throughput and reduces latency.

A. Decreasing the number of collision domains: While it is true that Ethernet switches decrease the number of collision domains, this is not a unique advantage over hubs. Hubs also decrease the number of collision domains by limiting the size of each collision domain to a single segment of the network. However, Ethernet switches further reduce collisions by forwarding frames only to the ports where the destination devices are located.

D. Increasing the size of broadcast domains: Ethernet switches do not increase the size of broadcast domains. In fact, switches limit the size of broadcast domains by forwarding frames only to the ports where the destination devices are located.

E. Increasing the maximum length of UTP cabling between devices: Ethernet switches do not increase the maximum length of UTP cabling between devices. The maximum length of UTP cabling is determined by the IEEE 802.3 standard, which specifies a maximum cable length of 100 meters.