In a shared Ethernet environment, what do machines do with frames not addressed to them?

In a shared Ethernet environment, what do machines do with frames not addressed to them?

• A. Broadcast to all devices
• B. Drop frames unconditionally
• C. Compare destination MAC and discard unmatched frames
• D. Ignore the frame and wait for retry

Answer: (C)

In a shared Ethernet environment, each network interface card only processes frames that are meant for it. When a frame arrives, the NIC looks at the destination MAC address and compares it to its own MAC. If the address matches, the frame is passed up to the host. If it doesn’t match, the NIC discards the frame to avoid wasting CPU cycles on data not intended for that device. This filtering keeps traffic efficient on a shared medium. Broadcast frames (destined for all devices) are an exception and are received by all NICs, but frames not addressed to a particular host are not forwarded to everyone. The other options would imply universal forwarding or waiting for a retry, which isn’t how Ethernet reception works.

In a shared Ethernet environment, each network interface card only processes frames that are meant for it. When a frame arrives, the NIC looks at the destination MAC address and compares it to its own MAC. If the address matches, the frame is passed up to the host. If it doesn’t match, the NIC discards the frame to avoid wasting CPU cycles on data not intended for that device. This filtering keeps traffic efficient on a shared medium. Broadcast frames (destined for all devices) are an exception and are received by all NICs, but frames not addressed to a particular host are not forwarded to everyone. The other options would imply universal forwarding or waiting for a retry, which isn’t how Ethernet reception works.