1. Announcement

2. Midterm Chapter 2 and 3 (see Reading List for details) Lab 1, 2, and 3

3. Midterm 1 A4-size Cheat Sheet Some MCQ/Short Questions

4. Problem Set 4 Clarification on Q3 Posted

5. Application Transport you are here Network Link Physical

6. Transport (process-to-process) Network (host-to-host) Link (node-to-node)

8. Transport (process-to-process) Network (host-to-host) IP ICMP Routing Protocols Link (node-to-node)

9. Routing

10. Internet is a “network of networks” A hierarchy of ISPs (Tier 1, 2, 3), each owns routers and links

11. Internet is a “network of Autonomous Systems” A hierarchy of ISPs (Tier 1, 2, 3), each owns routers and links

13. Intra-AS routing Inter-AS routing

14. Addr Interface X Y Z 1 1 3

15. 4,294,967,296

16. Prefix Interface 11001 110 011 1 2 3

17. Abstract View of Routing

20. 1 2 4 1 2 3 7 2 2

21. Shortest Path Problem in Graph

22. Link-State Routing Centralized, using Dijkstra algorithm

23. broadcast costs of links to each other

24. compute shortest paths locally (using global map)

25. Distance Vector Routing Distributed Asynchronous Iterative Self-Terminating

26. exchange “local views” with neighbors

27. update “local views” (based on neighbors’ view)

28. y x

29. y x

30. Bellman-FordEquation

31. v y x

32. 7 v 9 y 5 2 8 x 4

33. 7 9 y 5 v* 2 8 x 4

34. Dest Next y v*

35. Distance Vector

36. 1 2 y 7 x z

37. 1 2 y 7 x z

38. 5 1 y 2 w 2 7 x z

39. 1 4 y 50 x z

40. 1 4 y 50 x z

41. “Count-To-Infinity” Problem

42. PoisonedReverse

43. DV LS

44. 1 4 y 50 x z

45. RIP Routing Information Protocol

46. Routing Table

47. Exchange every 30 seconds(over UDP)

48. RIP “Self-Repair” if no ad from n for 180s assume n has failed

49. “static routing”“load insensitive”

50. Intra-AS routing Inter-AS routing