Discussion
Node X has a TCP connection open to node Y. The packets from X to Y go through an intermediate IP router R. Ethernet switch S is the first switch on the network path between X and R. Consider a packet sent from X to Y over this connection.
Which of the following statements is/are TRUE about the destination IP and MAC addresses on this packet at the time it leaves X?
Answer: B
The true statement is The destination IP address is the IP address of Y.
IP addresses are end to end: the packet carries Y's IP address as its destination all the way, and router R forwards it without changing that field. MAC addresses are hop by hop: X sends the frame to the next IP hop on its own network, which is router R, so the destination MAC address is R's.
R's IP address would be the destination only if the packet were addressed to the router itself. An Ethernet switch is transparent at layer 2 and does not appear as a frame's destination, so S's MAC address is wrong, and Y's MAC address is unknown to X because Y is on another network.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development