A host workstation generates a DNS query to resolve a hostname prior to establishing a connection. In what chronological sequence does the workstation's protocol stack perform outbound encapsulation on this data, from initial generation to physical media transmission?
- 1The client application formats the DNS request payload containing the domain name query.
- 2The UDP protocol prepends source and destination port numbers to form a datagram.
- 3The IP protocol prepends source and destination logical addresses to assemble a packet.
- 4The Ethernet protocol appends hardware MAC addresses and a Frame Check Sequence (FCS) to construct a frame.
Answer
The correct sequence starts with application payload formatting, followed by UDP transport header encapsulation (datagram creation), then IP network header encapsulation (packet creation), and concludes with Ethernet data link framing (frame creation).
Outbound encapsulation follows a strict top-down traversal of the OSI model stack. Data originates at the Application Layer where the raw DNS payload is created. It is passed to the Transport Layer (UDP), which appends port numbers to form a datagram. Next, the Network Layer (IP) adds IP addresses to form a packet. Finally, the Data Link Layer (Ethernet) adds MAC addresses and an FCS trailer to form a frame ready for physical bit transmission.
Step-by-Step Solution
Key Concept
Outbound OSI Encapsulation Flow
Estimated Time:1m 0s