1. The Network Layer Chapter 5 5.6

2. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 The Network Layer Principles (1) a)Make sure it works b)Keep it simple c)Make clear choices d)Exploit modularity e)Expect heterogeneity...

3. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 The Network Layer Principles (2) a)... 6.Avoid static options and parameters 7.Look for good design (not perfect) 8.Strict sending, tolerant receiving 9.Think about scalability 10.Consider performance and cost

4. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 The Network Layer in the Internet (1) a)The IP Version 4 Protocol b)IP Addresses c)IP Version 6 d)Internet Control Protocols e)Label Switching and MPLS f)OSPF—An Interior Gateway Routing Protocol g)BGP—The Exterior Gateway Routing Protocol h)Internet Multicasting i)Mobile IP

5. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 The Network Layer in the Internet (2) a)The Internet is an interconnected collection of many networks.

6. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 The IP Version 4 Protocol (1) a)The IPv4 (Internet Protocol) header.

7. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 The IP Version 4 Protocol (2) a)Some of the IP options.

8. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 IP Addresses (1) a)An IP prefix.

9. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 IP Addresses (2) a)Splitting an IP prefix into separate networks with subnetting.

10. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 IP Addresses (3) a)A set of IP address assignments

11. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 IP Addresses (4) a)Aggregation of IP prefixes

12. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 IP Addresses (5) a)Longest matching prefix routing at the New York router.

13. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 IP Addresses (6) a)IP address formats

14. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 IP Addresses (7) a)Special IP addresses

15. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 IP Addresses (8) a)Placement and operation of a NAT box.

16. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 IP Version 6 Goals a)Support billions of hosts b)Reduce routing table size c)Simplify protocol d)Better security e)Attention to type of service f)Aid multicasting g)Roaming host without changing address h)Allow future protocol evolution i)Permit coexistence of old, new protocols...

17. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 IP Version 6 (1) a)The IPv6 fixed header (required).

18. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 IP Version 6 (2) a)IPv6 extension headers

19. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 IP Version 6 (3) a)The hop-by-hop extension header for large datagrams (jumbograms).

20. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 IP Version 6 (4) a)The extension header for routing.

21. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 Internet Control Protocols (1) a)The principal ICMP message types.

22. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 Internet Control Protocols (2) a)Two switched Ethernet LANs joined by a router

23. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 Label Switching and MPLS (1) a)Transmitting a TCP segment using IP, MPLS, and PPP.

24. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 Label Switching and MPLS (2) a)Forwarding an IP packet through an MPLS network

25. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 OSPF—An Interior Gateway Routing Protocol (1) a)An autonomous system

26. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 OSPF—An Interior Gateway Routing Protocol (2) a)A graph representation of the previous slide.

27. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 OSPF—An Interior Gateway Routing Protocol (3) a)The relation between ASes, backbones, and areas in OSPF.

28. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 OSPF—An Interior Gateway Routing Protocol (4) a)The five types of OSPF messages

29. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 BGP—The Exterior Gateway Routing Protocol (1) a)Examples of routing constraints: b)No commercial traffic for educat. network c)Never put Iraq on route starting at Pentagon d)Choose cheaper network e)Choose better performing network f)Don’t go from Apple to Google to Apple

30. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 BGP—The Exterior Gateway Routing Protocol (2) a)Routing policies between four Autonomous Systems

31. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 BGP—The Exterior Gateway Routing Protocol (3) a)Propagation of BGP route advertisements

32. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 Mobile IP a)Goals b)Mobile host use home IP address anywhere. c)No software changes to fixed hosts d)No changes to router software, tables e)Packets for mobile hosts – restrict detours f)No overhead for mobile host at home.

33. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 End a)Chapter 5