Interactive end-of-chapter exercises


IPv6 Tunneling and Encapsulation

Consider the network shown below which contains four IPv6 subnets, connected by a mix of IPv6-only routers(shaded blue), IPv4-only routers (shaded red) and dual-capable IPv6/IPv4 routers (shaded blue with red interfaces to IPv4 routers). You might want to review Section 4.3.4 in the textbook before doing this problem.


Suppose that a host of subnet D wants to send an IPv6 datagram to a host on subnet A. Assume that the forwarding between these two hosts goes along the path: D --> F --> b --> d --> c --> a --> C --> A



Question List


1. Is the datagram being forwarded from D to F an IPv4 or IPv6 datagram?

2. What is the source address of this D to F datagram?

3. What is the destination address of this D to F datagram?

4. Is this D to F datagram encapsulating another datagram? Yes or No.

5. Is the datagram being forwarded from F to b an IPv4 or IPv6 datagram?

6. What is the source address of this F to b datagram?

7. What is the destination address of this F to b datagram?

8. Is this F to b datagram encapsulating another datagram? Yes or No.

9. What is the source address of this encapsulated datagram?

10. What is the destination address of this encapsulated datagram?

11. Is the datagram being forwarded from b to d an IPv4 or IPv6 datagram?

12. What is the source address of this b to d datagram?

13. What is the destination address of this b to d datagram?

14. Is this b to d datagram encapsulating another datagram? Yes or No.

15. What is the source address of this encapsulated datagram?

16. What is the destination address of this encapsulated datagram?

17. Is the datagram being forwarded from d to c an IPv4 or IPv6 datagram?

18. What is the source address of this d to c datagram?

19. What is the destination address of this d to c datagram?

20. Is this d to c datagram encapsulating another datagram? Yes or No.

21. What is the source address of this encapsulated datagram?

22. What is the destination address of this encapsulated datagram?

23. Is the datagram being forwarded from c to a an IPv4 or IPv6 datagram?

24. What is the source address of this c to a datagram?

25. What is the destination address of this c to a datagram?

26. Is this c to a datagram encapsulating another datagram? Yes or No.

27. What is the source address of this encapsulated datagram?

28. What is the destination address of this encapsulated datagram?

29. Is the datagram being forwarded from a to C an IPv4 or IPv6 datagram?

30. What is the source address of this a to C datagram?

31. What is the destination address of this a to C datagram?

32. Is this a to C datagram encapsulating another datagram? Yes or No.

33. What is the source address of this encapsulated datagram?

34. What is the destination address of this encapsulated datagram?

35. Is the datagram being forwarded from C to A an IPv4 or IPv6 datagram?

36. What is the source address of this C to A datagram?

37. What is the destination address of this C to A datagram?

38. Is this C to A datagram encapsulating another datagram? Yes or No.

39. What router is the 'tunnel entrance'? Give the router's letter

40. What router is the 'tunnel exit'? Give the router's letter

41. Which protocol encapsulates the other, IPv4 or IPv6?




Solution


1. The datagram is an IPv6 datagram.

2. The source IP address is 16BA:A86F:3A87:2EFD:1C45:43DD:194F:9EE4

3. The destination IP address is DB83:15D2:ADD4:81BB:F4E7:5478:D8E7:9EF3

4. No, the datagram is NOT encapsulated.

5. The datagram is an IPv4 datagram.

6. The source IP address is 220.69.14.244

7. The destination IP address is 201.211.108.245

8. Yes, the datagram is encapsulated.

9. The source address of this encapsulated datagram is 16BA:A86F:3A87:2EFD:1C45:43DD:194F:9EE4

10. The destination address of this encapsulated datagram is DB83:15D2:ADD4:81BB:F4E7:5478:D8E7:9EF3

11. The datagram is an IPv4 datagram.

12. The source IP address is 220.69.14.244

13. The destination IP address is 201.211.108.245

14. Yes, the datagram is encapsulated.

15. The source address of this encapsulated datagram is 16BA:A86F:3A87:2EFD:1C45:43DD:194F:9EE4

16. The destination address of this encapsulated datagram is DB83:15D2:ADD4:81BB:F4E7:5478:D8E7:9EF3

17. The datagram is an IPv4 datagram.

18. The source IP address is 220.69.14.244

19. The destination IP address is 201.211.108.245

20. Yes, the datagram is encapsulated.

21. The source address of this encapsulated datagram is 16BA:A86F:3A87:2EFD:1C45:43DD:194F:9EE4

22. The destination address of this encapsulated datagram is DB83:15D2:ADD4:81BB:F4E7:5478:D8E7:9EF3

23. The datagram is an IPv4 datagram.

24. The source IP address is 220.69.14.244

25. The destination IP address is 201.211.108.245

26. Yes, the datagram is encapsulated.

27. The source address of this encapsulated datagram is 16BA:A86F:3A87:2EFD:1C45:43DD:194F:9EE4

28. The destination address of this encapsulated datagram is DB83:15D2:ADD4:81BB:F4E7:5478:D8E7:9EF3

29. The datagram is an IPv4 datagram.

30. The source IP address is 220.69.14.244

31. The destination IP address is 201.211.108.245

32. Yes, the datagram is encapsulated.

33. The source address of this encapsulated datagram is 16BA:A86F:3A87:2EFD:1C45:43DD:194F:9EE4

34. The destination address of this encapsulated datagram is DB83:15D2:ADD4:81BB:F4E7:5478:D8E7:9EF3

35. The datagram is an IPv6 datagram.

36. The source IP address is 16BA:A86F:3A87:2EFD:1C45:43DD:194F:9EE4

37. The destination IP address is DB83:15D2:ADD4:81BB:F4E7:5478:D8E7:9EF3

38. No, the datagram is NOT encapsulated.

39. The tunnel entrance is router F

40. The tunnel exit is router C

41. IPv4, in order to maintain compatibility with existing IPv4 infrastructure, IPv6 datagrams are put in the payload of an IPv4 datagram. These IPv4 datagrams are passed on until it reaches a router which supports IPv6, where the IPv6 datagram is decapsulated and passed on.



That's incorrect

That's correct

The answer was: IPv6

Question 1 of 41

The answer was: 16BA:A86F:3A87:2EFD:1C45:43DD:194F:9EE4

Question 2 of 41

The answer was: DB83:15D2:ADD4:81BB:F4E7:5478:D8E7:9EF3

Question 3 of 41

The answer was: No

Question 4 of 41

The answer was: IPv4

Question 5 of 41

The answer was: 220.69.14.244

Question 6 of 41

The answer was: 201.211.108.245

Question 7 of 41

The answer was: Yes

Question 8 of 41

The answer was: 16BA:A86F:3A87:2EFD:1C45:43DD:194F:9EE4

Question 9 of 41

The answer was: DB83:15D2:ADD4:81BB:F4E7:5478:D8E7:9EF3

Question 10 of 41

The answer was: IPv4

Question 11 of 41

The answer was: 220.69.14.244

Question 12 of 41

The answer was: 201.211.108.245

Question 13 of 41

The answer was: Yes

Question 14 of 41

The answer was: 16BA:A86F:3A87:2EFD:1C45:43DD:194F:9EE4

Question 15 of 41

The answer was: DB83:15D2:ADD4:81BB:F4E7:5478:D8E7:9EF3

Question 16 of 41

The answer was: IPv4

Question 17 of 41

The answer was: 220.69.14.244

Question 18 of 41

The answer was: 201.211.108.245

Question 19 of 41

The answer was: Yes

Question 20 of 41

The answer was: 16BA:A86F:3A87:2EFD:1C45:43DD:194F:9EE4

Question 21 of 41

The answer was: DB83:15D2:ADD4:81BB:F4E7:5478:D8E7:9EF3

Question 22 of 41

The answer was: IPv4

Question 23 of 41

The answer was: 220.69.14.244

Question 24 of 41

The answer was: 201.211.108.245

Question 25 of 41

The answer was: Yes

Question 26 of 41

The answer was: 16BA:A86F:3A87:2EFD:1C45:43DD:194F:9EE4

Question 27 of 41

The answer was: DB83:15D2:ADD4:81BB:F4E7:5478:D8E7:9EF3

Question 28 of 41

The answer was: IPv4

Question 29 of 41

The answer was: 220.69.14.244

Question 30 of 41

The answer was: 201.211.108.245

Question 31 of 41

The answer was: Yes

Question 32 of 41

The answer was: 16BA:A86F:3A87:2EFD:1C45:43DD:194F:9EE4

Question 33 of 41

The answer was: DB83:15D2:ADD4:81BB:F4E7:5478:D8E7:9EF3

Question 34 of 41

The answer was: IPv6

Question 35 of 41

The answer was: 16BA:A86F:3A87:2EFD:1C45:43DD:194F:9EE4

Question 36 of 41

The answer was: DB83:15D2:ADD4:81BB:F4E7:5478:D8E7:9EF3

Question 37 of 41

The answer was: No

Question 38 of 41

The answer was: F

Question 39 of 41

The answer was: C

Question 40 of 41

The answer was: IPv4

Question 41 of 41

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We greatly appreciate the work of John Broderick (UMass '21) in helping to develop these interactive problems.

Copyright © 2010-2025 J.F. Kurose, K.W. Ross
Comments welcome and appreciated: kurose@cs.umass.edu