CCNA: Cisco Certified Network Associate — Question 109

Which component of an Ethernet frame is used to notify a host that traffic is coming?

Answer options

• A. start of frame delimiter
• B. Type field
• C. preamble
• D. Data field

Correct answer: C

Explanation

The preamble is the component that signals to the receiving device that a frame is incoming, allowing it to prepare for the data transmission. The start of frame delimiter marks the beginning of the frame but does not serve the purpose of notifying the host about incoming traffic. The Type field indicates the protocol used in the data but does not assist in signaling the start of transmission. The Data field contains the actual payload of the frame and is not involved in notifying the host.