CCNA Routing and Switching (legacy) — Question 153

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: B

Explanation

The Type field in an Ethernet frame indicates the protocol type of the encapsulated data, thereby notifying the host about incoming traffic. The start of frame delimiter and preamble serve different purposes, such as indicating the start of the frame and synchronization, while the Data field contains the actual payload being transmitted.