1. TCP/IP Overview

2. 2 Upon completion of this chapter you will be able to perform the following tasks: Describe how the TCP/IP implementation relates to the OSI reference model Identify the functions of the TCP/IP network- layer protocols Identify the functions of the TCP/IP transport- layer protocols Objectives

3. 3 Early of 1970s Developed as part of the research done by the Defense Advanced Research Projects Agency (DARPA) Later TCP/IP was included with the Berkeley Software Distribution (BSD) of UNIX Universal Introduction to TCP/IP UNIX Host Internet TCP/IP UNIX Host

4. 4 TCP/IP Protocol Stack Map DOD model to the OSI Reference Model Application Presentation Session Transport Network Data Link Physical 7 6 5 4 3 2 1 Application Transport Internet Network Interface OSI Reference Model Ethernet, 802.3, 802.5, FDDI, and so on. TCP/IP Conceptual Layers US Department Of Defence (DOD)

5. Internet Layer

6. 6 Network Layer Overview OSI network layer corresponds to the TCP/IP internet layer Internet Protocol (IP) Internet Control Message Protocol (ICMP) Address Resolution Protocol (ARP) Reverse Address Resolution Protocol (RARP) Internet Protocol (IP) Internet Control Message Protocol (ICMP) Address Resolution Protocol (ARP) Reverse Address Resolution Protocol (RARP) Application Transport Internet Network Interface Hardware

7. 7 IP Datagram # Bits616324166 32 VERSHLEN Type of Service Total Length Identi- fication Flags Frag Offset TTL 4 # Bits1632416 32 Protocol Header Checksum Source IP Address Destination IP Address IP Options Data… 4 Network Header Segment Header Frame Trailer Frame Header Data

8. IP Address

9. 9 Unique addressing allows communication between end stations Path choice is based on location Location is represented by an address Introduction to TCP/IP Addresses UNIX Host Company A Company B 172.16.3.1010.250.8.11

10. 10 32 Bits NetworkHost IP Addressing

11. 11 IP Addressing 32 Bits NetworkHost 8 Bits 10101100000100001100110001111010

12. 12 IP Addressing 32 Bits NetworkHost 8 Bits 172. 16. 122. 204 8 Bits 10101100000100001100110001111010 00000000 ~ 11111111 ( binary ) ––– 0 ~ 255 ( Decimal )

13. 13 Class A: Class B: Class C: Class D: For Multicast Class E: For Research N = Network number H = Host number IP Address Classes NHHHNNHHNNNH

14. 14 IP Address Bit Patterns 1724 Class A: # Bits 0network #host #

15. 15 IP Address Bit Patterns 1724 Class A: # Bits 1416 Class B: # Bits 0network #host # 1network #host #0 2

16. 16 IP Address Bit Patterns 1724 Class A: # Bits 1416 Class B: # Bits 3218 Class C: # Bits 0network #host # 1network #host #0 1network #host #10 2

17. 17 IP Address Bit Patterns Class D: # Bits 1 1 1 0 1 Class E: # Bits 1 1 1 1 1 Multicast For Research

18. 18 Network 172.16.0.0 Host 0.0.3.10 Host 0.0.3.15 172.16.0.0 Addressing Example 172.16.3.10 172.16.3.15

19. 19 Recognizing Classes in IP Addresses (First Octet Rule) High Order Bits (binary ) Octet in Decimal Address Class 0 10 110 1110 1111 1 – 126 128 – 191 192 – 223 224 – 239 240 – 255 ABCDEABCDE Network 127.0.0.0 Reserved for loopback. The address 127.0.0.1 often is used to refer to the local host

20. 20 Address Rule: · All network bits set to 0 Refers to a host on “this” network For example, 0.0.0.34 would address node 34 on the local network · All host bits set to 0 Refers to the network itself For example, the address 172.16.0.0 can be used to refer to network 172.16 · All network bits set to 1 Refers to a Subnet Mask For example, the address 255.255.0.0 · All host bits set to 1 Refers to Broadcast Addresses For example, the address 172.16. 255.255 · 255.255.255.255 Refers to a broadcast meant for hosts on this network only · Network 0.0.0.0 Refers to the default route

21. 21 Network And Host Number Address Class Network Number Host Number ABCABC 126 16,384 2,097,152 16,777,214 65,534 254 Network 126= 2 7 -1 (127.0.0.0 Reserved) 16384 = 2 14 2,097,152 = 2 21 Host 16,777,214 = 2 24 - 2 65,534 = 2 16 - 2 254 = 2 8 - 2

22. 22 AddressClassNetworkHost 10.2.1.1 128.63.2.100 201.222.5.64 192.6.141.2 130.113.64.16 256.241.201.10 Exercise: IP Address Classes

23. 23 AddressClassNetworkHost Exercise: IP Address Classes 10.2.1.1 128.63.2.100 201.222.5.64 192.6.141.2 130.113.64.16 256.241.201.10 A

24. 24 Exercise: IP Address Classes AddressClassNetworkHost 10.2.1.1 128.63.2.100 201.222.5.64 192.6.141.2 130.113.64.16 256.241.201.10 A 10.0.0.0

25. 25 Exercise: IP Address Classes AddressClassNetworkHost 10.2.1.1 128.63.2.100 201.222.5.64 192.6.141.2 130.113.64.16 256.241.201.10 A 0.2.1.1 10.0.0.0

26. 26 Exercise: IP Address Classes AddressClassNetworkHost 10.2.1.1 128.63.2.100 201.222.5.64 192.6.141.2 130.113.64.16 256.241.201.10 A B 0.2.1.1 10.0.0.0

27. 27 Exercise: IP Address Classes AddressClassNetworkHost 10.2.1.1 128.63.2.100 201.222.5.64 192.6.141.2 130.113.64.16 256.241.201.10 A B 128.63.0.0 0.2.1.1 10.0.0.0

28. 28 Exercise: IP Address Classes AddressClassNetworkHost 10.2.1.1 128.63.2.100 201.222.5.64 192.6.141.2 130.113.64.16 256.241.201.10 A B 0.0.2.100 128.63.0.0 0.2.1.1 10.0.0.0

29. 29 Exercise: IP Address Classes AddressClassNetworkHost 10.2.1.1 128.63.2.100 201.222.5.64 192.6.141.2 130.113.64.16 256.241.201.10 A B C 0.0.2.100 128.63.0.0 0.2.1.1 10.0.0.0

30. 30 Exercise: IP Address Classes AddressClassNetworkHost 10.2.1.1 128.63.2.100 201.222.5.64 192.6.141.2 130.113.64.16 256.241.201.10 A B C 201.222.5.0 0.0.2.100 128.63.0.0 0.2.1.1 10.0.0.0

31. 31 Exercise: IP Address Classes AddressClassNetworkHost 10.2.1.1 128.63.2.100 201.222.5.64 192.6.141.2 130.113.64.16 256.241.201.10 A B C 0.0.0.64 201.222.5.0 0.0.2.100 128.63.0.0 0.2.1.1 10.0.0.0

32. 32 Exercise: IP Address Classes AddressClassNetworkHost 10.2.1.1 128.63.2.100 201.222.5.64 192.6.141.2 130.113.64.16 256.241.201.10 A B C C B 0.0.64.16 130.113.0.0 0.0.0.2 192.6.141.0 0.0.0.64 201.222.5.0 0.0.2.100 128.63.0.0 0.2.1.1 10.0.0.0 Nonexistent 00000000 ~ 11111111 ( binary ) ––– 0 ~ 255 ( Decimal )

33. 33 The Internet is controlled by a number of bodies ISOC (Internet Society)—non-profit society coordinating internet evolution and use. IANA (Internet Assigned Numbers Authority)—organization operated under ISOC as part of the Internet Architecture Board (IAB). Delegates authority for IP address space allocation and domain name assignment to the InterNIC and other organizations. InterNIC (Network Information Center)—an independent agency that makes rules, administers the registration process, and maintains the official database of registered domain names. The Domain Name System (DNS) is a set of distributed databases containing these numeric equivalents and their corresponding domain names. With the DNS system users may use an easy-to- remember name (yourname.com) rather than a difficult string of numbers when seeking out a site on the Internet.

34. 34 Addresses for Private Networks Class Beginning Address Ending Address Class A 10.0.0.0 10.255.255.255 Class B 172.16.0.0 172.31.255.255 Class C 192.168.0.0 192.168.255.255 The others are registered addresses If you are connected to the Internet, you must use registered addresses

35. Configuring IP Addresses

36. 36 Host Addresses 172.16.2.2 172.16.3.10 172.16.12.12 IP: 172.16.2.1 10.1.1.1 10.250.8.11 10.180.30.118 IP: 10.6.24.2 E0E1 172.1612 NetworkHost.. NetworkInterface 172.16.0.0 10.0.0.0 E0 E1 Routing Table

37. 37 Network 172.16.0.0 172.16.0.0 Standard Address

38. 38 Network 172.16.0.0 Addressing with Subnets 172.16.1.0172.16.2.0 172.16.3.0 172.16.4.0 Company A 172.18.0.0 172.16.0.0172.17.0.0

39. 39 Subnet Addressing 172.16.?.200 172.16.?.2 172.16. ?.160 172.16.?.5 172.16. ?.100 172.16. ?.150 E0E1 NetworkInterface 172.16.0.0 E0 E1 Routing Table

40. 40 Subnet Addressing 172.16.2.200 172.16.2.2 172.16.2.160 IP: 172.16.2.1 172.16.3.5 172.16.3.100 172.16.3.150 IP: 172.16.3.1 E0E1 172.162160 NetworkHost.. Subnet 172.163100 NetworkHost.. Subnet NetworkInterface 172.16.2.0 172.16.3.0 E0 E1 New Routing Table

41. 41 Subnet Mask 1721600 IP Address NetworkHost

42. 42 Subnet Mask 1721600255 00 IP Address Default Subnet Mask NetworkHost NetworkHost

43. 43 Subnet Mask 1721600 255 00 0 IP Address Default Subnet Mask Additional 8-bit Subnet Mask NetworkHost Borrow from host bits, starting at the high order bit position NetworkHost NetworkSubnetHost

44. 44 Decimal Equivalents of Bit Patterns 10000000=128 11000000=192 11100000=224 11110000=240 11111000=248 11111100=252 11111110=254 11111111=255 128 6432168421

45. 45 Network Host 172.16.2.160 255.255.0.0 1721600 10101100 11111111 10101100 00010000 11111111 00010000 00000000 10100000 00000000 Subnets not in use—the default 00000010 Standard Address without Subnets

46. 46 NetworkHost 172.16.2.160 255.255.255.0 1721620 Subnet 11111111 00000000 11111111 Network number extended by eight bits 10101100 00010000 00000010 10100000 00000000 00000010 Subnet Mask with Subnets

47. 47 NetworkHost 172.16.98.160 255.255.224.0 17216960 Subnet 11111111 00000000 11100000 Network number extended by variable bits 10101100 00010000 01100000 10100000 00000000 01100010 Subnet Mask with Subnets

48. 48 Decimal Equivalents of Bit Patterns 10000000=128 11000000=192 11100000=224 11110000=240 11111000=248 11111100=252 11111110=254 11111111=255 128 6432168421

49. 49 Exercise: Subnet Masks AddressSubnet MaskClassSubnet 172.16.2.10 10.13.24.20 10.30.36.12 255.255.255.0 255.252.0.0 255.255.255.0

50. 50 Exercise: Subnet Masks AddressSubnet MaskClassSubnet 172.16.2.10 10.13.24.20 10.30.36.12 255.255.255.0 255.252.0.0 255.255.255.0 B

51. 51 Exercise: Subnet Masks AddressSubnet MaskClassSubnet 172.16.2.10 10.13.24.20 10.30.36.12 255.255.255.0 255.252.0.0 255.255.255.0 B172.16.2.0

52. 52 Exercise: Subnet Masks AddressSubnet MaskClassSubnet 172.16.2.10 10.13.24.20 10.30.36.12 255.255.255.0 255.252.0.0 255.255.255.0 B A 172.16.2.0

53. 53 Exercise: Subnet Masks AddressSubnet MaskClassSubnet 172.16.2.10 10.13.24.20 10.30.36.12 255.255.255.0 255.252.0.0 255.255.255.0 B A 172.16.2.0 10.12.0.0 10.13.24.20 255.252.0.0 1111111111111100 00000000 00001010 00001101 00001100 00000000 00010100 00000000 00011000 10. 12. 0. 0

54. 54 Exercise: Subnet Masks AddressSubnet MaskClassSubnet 172.16.2.10 10.13.24.20 10.30.36.12 255.255.255.0 255.252.0.0 255.255.255.0 B A A 172.16.2.0 10.12.0.0

55. 55 Exercise: Subnet Masks AddressSubnet MaskClassSubnet 172.16.2.10 10.13.24.20 10.30.36.12 255.255.255.0 255.252.0.0 255.255.255.0 B A A 172.16.2.0 10.12.0.0 10.30.36.0

56. 56 Subnet Planning Other subnets 20 subnets 5 hosts per subnet Class C address: 201.222.5.0 20 subnets 5 hosts per subnet Class C address: 201.222.5.0 201.222.5.16 201.222.5.32201.222.5.48 20 subnets 5 Bits of Subnet 2 5 =32 Subnets 5 hosts per subnet 3 Bits of Host 2 3 -2= 6 Hosts 20 subnets 5 Bits of Subnet 2 5 =32 Subnets 5 hosts per subnet 3 Bits of Host 2 3 -2= 6 Hosts

57. 57 IP Host Address:201.222.5.121 Subnet Mask: 255.255.255.248 NetworkSubnetHost 2012225120 201.222.5.121:11001001 11111111 Subnet:1100100111011110 11111111 00000101 11111111 01111 001 11111 000 01111 000 255.255.255.248: Class C Subnet Planning Example Subnet Address = 201.222.5.120 Host Addresses = 0.0.0.1 Rang = 201.222.5.121–201.222.5.126 Broadcast Address = 201.222.5.127 Five Bits of Subnetting

58. 58 IP Host Address:172.16.2.120 Subnet Mask: 255.255.255.0 Subnet Address = 172.16.2.0 Host Addresses = 172.16.2.1–172.16.2.254 Broadcast Address = 172.16.2.255 Eight bits of subnetting Network Subnet Host 1721620 172.16.2.120: 255.255.255.0: 10101100 11111111 Subnet:1010110000010000 11111111 00000010 11111111 01111001 00000000 Class B Subnet Planning Example

59. 59 Broadcast Addresses 172.16.1.0 172.16.2.0 172.16.3.0 172.16.4.0 172.16.3.255 (Directed broadcast) 255.255.255.255 (Local network broadcast) X

60. 60 Exercise: Broadcast Addresses AddressClassSubnetBroadcast 201.222.10.60255.255.255.248 Subnet Mask 15.16.193.6255.255.248.0 128.16.32.13255.255.255.252

61. 61 AddressClassSubnetBroadcast 201.222.10.60255.255.255.248C Subnet Mask 15.16.193.6255.255.248.0 128.16.32.13255.255.255.252 Exercise: Broadcast Addresses

62. 62 AddressClassSubnetBroadcast 201.222.10.60255.255.255.248C201.222.10.56 Subnet Mask 15.16.193.6255.255.248.0 128.16.32.13255.255.255.252 Exercise: Broadcast Addresses 60 --- 0011110056 --- 00111000

63. 63 AddressClassSubnetBroadcast 201.222.10.60255.255.255.248C201.222.10.63201.222.10.56 Subnet Mask 15.16.193.6255.255.248.0 128.16.32.13255.255.255.252 Exercise: Broadcast Addresses 63 --- 0011111156 --- 0011100060 --- 00111100

64. 64 AddressClassSubnetBroadcast 201.222.10.60255.255.255.248C201.222.10.63201.222.10.56 Subnet Mask 15.16.193.6255.255.248.0A 128.16.32.13255.255.255.252 Exercise: Broadcast Addresses

65. 65 AddressClassSubnetBroadcast 201.222.10.60255.255.255.248C201.222.10.63201.222.10.56 Subnet Mask 15.16.193.6255.255.248.0A15.16.192.0 128.16.32.13255.255.255.252 Exercise: Broadcast Addresses 193 --- 11000001192 --- 11000000

66. 66 AddressClassSubnetBroadcast 201.222.10.60255.255.255.248C201.222.10.63201.222.10.56 Subnet Mask 15.16.193.6255.255.248.0A15.16.199.25515.16.192.0 128.16.32.13255.255.255.252 Exercise: Broadcast Addresses 199 --- 11000111 255 --- 11111111 192 --- 11000000193 --- 11000001

67. 67 AddressClassSubnetBroadcast 201.222.10.60255.255.255.248C201.222.10.63201.222.10.56 Subnet Mask 15.16.193.6255.255.248.0A15.16.199.25515.16.192.0 128.16.32.13255.255.255.252B Exercise: Broadcast Addresses

68. 68 AddressClassSubnetBroadcast 201.222.10.60255.255.255.248C201.222.10.63201.222.10.56 Subnet Mask 15.16.193.6255.255.248.0A15.16.199.25515.16.192.0 128.16.32.13255.255.255.252B128.16.32.12 Exercise: Broadcast Addresses 12 --- 0000110013 --- 00001101

69. 69 AddressClassSubnetBroadcast 201.222.10.60255.255.255.248C201.222.10.63201.222.10.56 Subnet Mask 15.16.193.6255.255.248.0A15.16.199.25515.16.192.0 128.16.32.13255.255.255.252B128.16.32.15128.16.32.12 Exercise: Broadcast Addresses 15 --- 0000111112 --- 0000110013 --- 00001101

70. 70 IP addresses are specified in 32-bit dotted-decimal format that indicates class, network, and host identifications Subnet masks are used to indicate the boundary between network, subnet, and host IDs Subnet Planning Broadcast Addresses Subnets with all [0]s or all [1]s reserved IP addresses Summary

71. 71 Internet Control Message Protocol Application Transport Internet Network Interface Hardware ICMP Destination Unreachable Echo (Ping) Other ICMP messages are carried in IP datagrams and are used to send error and control messages

72. 72 Internet Control Message Protocol Application Transport Internet Network Interface Hardware ICMP Destination Unreachable Echo (Ping) Other · Destination Unreachable · Time Exceeded · Parameter Problem · Source Quench · Redirect · Echo Request · Echo Reply · Timestamp · Timestamp Reply · Information Request · Information Reply · Address Request · Address Reply

73. 73 ICMP Testing Destination unreachable –Host or port unreachable –Network unreachable Host A I do not know how to get to Z. Send ICMP. To Z Destination Unreachable Send data to Z. Data Network

74. 74 ICMP Testing (cont.) Generated by the ping command A Yes, I am here. Is B reachable? B

75. 75 ICMP Testing (cont.) Generated by the ping command A Yes, I am here. Is B reachable? B ICMP Echo Request

76. 76 ICMP Testing (cont.) Generated by the ping command A Yes, I am here. ICMP Echo Reply Is B reachable? B ICMP Echo Request

77. 77 Address Resolution Protocol 172.16.3.1 172.16.3.2 IP: 172.16.3.2 = ??? I need the Ethernet address of 176.16.3.2.

78. 78 Address Resolution Protocol 172.16.3.1 IP: 172.16.3.2 Ethernet: 0800.0020.1111 172.16.3.2 IP: 172.16.3.2 = ??? I need the Ethernet address of 176.16.3.2. I heard that broadcast. The message is for me. Here is my Ethernet address.

79. 79 Address Resolution Protocol Map IP Ethernet Local ARP 172.16.3.1 IP: 172.16.3.2 Ethernet: 0800.0020.1111 172.16.3.2 IP: 172.16.3.2 = ??? I need the Ethernet address of 176.16.3.2. I heard that broadcast. The message is for me. Here is my Ethernet address. Example 1: Destination local

80. 80 Finding the MAC Address Router A Example 2: Destination not local Host Z Host Y Query Broadcast Host Z MAC ? Host Z MAC ? Host Z Response Host Y MAC Host Y MAC Router A MAC Router A MAC Routing Table: Net for Host Z Routing Table: Net for Host Z Map IP Ethernet Not Local ARP

81. Transport Layer

82. 82 Transport Layer Overview Transmission Control Protocol (TCP) User Datagram Protocol (UDP) Transmission Control Protocol (TCP) User Datagram Protocol (UDP) Application Transport Internet Network Interface Hardware TCP : Connection-oriented services UDP : Connectionless services

83. 83 Determines destination upper-layer protocol IP Datagram Protocol Field Transport Layer Internet Layer TCP UDP Protocol Numbers IP 176

84. 84 IP Datagram # Bits616324166 32 VERSHLEN Type of Service Total Length Identi- fication Flags Frag Offset TTL 4 # Bits1632416 32 Protocol Header Checksum Source IP Address Destination IP Address IP Options Data… 4 Network Header Segment Header Frame Trailer Frame Header Data

85. 85 TCP Segment Format # Bits616324166 32 Source Port Dest. Port Sequence Number Acknowledgement Number HLENReserved Code Bits 16 Window 16 Check- sum 16 Urgent 0 or 32 OptionData...

86. 86 Port Numbers TCP Port Numbers FTPFTP Transport Layer TELNETTELNET DNSDNS SNMPSNMP TFTPTFTP SMTPSMTP UDP Application Layer 2123255369161

87. 87 Port Numbers assigned range Port numbers have the following assigned ranges: Port number are 16 bits long (0~65536) Numbers below 1 to 255 are for public applications (well-known port number ) Numbers from 256 to 1023 are assigned to companies for saleable applications Numbers above 1023 are unregulated

88. 88 Identify Service 172.16.1.51 72.16.1.2 172.16.1.1 Client_1Client_2 DNS FTP Server 102853… SPDP 102821… SPDP 5321 172.16.1.101

89. 89 TCP Port Numbers Source Port Dest. Port … Host A Dest. port = 23. Send packet to my Telnet application. 102823… SPDP Host Z Telnet Z

90. 90 Send SYN (seq=100 ctl=SYN) Host AHost B 1 TCP Three-Way Handshake/Open Connection SYN received (seq=100)

91. 91 Send SYN (seq=100 ctl=SYN) SYN received (seq=100 ) Send SYN (seq=300 ack=101 ctl=syn,ack) Host AHost B 1 2 SYN received (seq=300 ack=101) TCP Three-Way Handshake/Open Connection

92. 92 Send SYN (seq=100 ctl=SYN) SYN received (seq=100 ) Send SYN (seq=300 ack=101 ctl=syn,ack) Send ack (ack=301 ctl=ack) Host AHost B 1 2 3 SYN received (seq=300 ack=101) TCP Three-Way Handshake/Open Connection

93. 93 TCP Three-Way Handshake/Open Connection Send SYN (seq=100 ctl=SYN) SYN received (seq=100 ) Send SYN (seq=300 ack=101 ctl=syn,ack) Send ack (ack=301 ctl=ack) Host AHost B Established Connection (seq=101 ctl= Data) 1 2 3 SYN received (seq=300 ack=101) SYN received (ack=301 )

94. 94 TCP Windowing Sender Receiver

95. 95 Window size = 3 Send 2 TCP Windowing Sender Receiver Window size = 3 Send 1 Window size = 3 Send 3

96. 96 Window size = 3 Send 2 TCP Windowing Sender Receiver Window size = 3 Send 1 Window size = 3 Send 3 ACK 1 Window size = 2 ACK 2 Window size = 2 ACK 3 Window size = 2

97. 97 Window size = 3 Send 5 Window size = 3 Send 2 TCP Windowing Sender Receiver Window size = 3 Send 1 Window size = 3 Send 4 Window size = 3 Send 3 ACK 1 Window size = 2 ACK 2 Window size = 2 ACK 3 Window size = 2

98. 98 Window size = 3 Send 5 Window size = 3 Send 2 TCP Windowing Sender Receiver Window size = 3 Send 1 Window size = 3 Send 4 Window size = 3 Send 3 ACK 1 Window size = 2 ACK 2 Window size = 2 ACK 3 Window size = 2 ACK 4 Window size = 2 ACK 5 Window size = 2

99. 99 TCP Sequence and Acknowledgment Numbers I just sent #10. Source Port Dest. Port … Sequence # Acknowledgement # 102823 SourceDest. 10 Seq. 0 Ack. …

100. 100 TCP Sequence and Acknowledgment Numbers I just sent #10. I just got #10, now I need #11. Source Port Dest. Port … Sequence # Acknowledgement # 102823 SourceDest. 10 Seq. 1 Ack. … 102823 SourceDest. 11 Seq. 1 Ack. …

101. 101 TCP Sequence and Acknowledgment Numbers I just sent #10. I just got #10, now I need #11. Source Port Dest. Port … Sequence # Acknowledgement # 102823 SourceDest. 10 Seq. 1 Ack. … 102823 SourceDest. 11 Seq. 2 Ack. … 102823 SourceDest. 11 Seq. 1 Ack. … Sequence and Reliability

102. 102 UDP no sequence or acknowledgment fields Application-layer protocols can provide for reliability UDP Segment Format 16 Source Port 16 Destination Port 16 Length 16 ChecksumData… # Bits

103. 103 Application Layer Overview *Used by the router Application Transport Internet Network Interface Hardware File Transfer - TFTP * - FTP - NFS E-Mail - SMTP Remote Login - Telnet * - rlogin Network Management - SNMP * Name Management - DNS* File Transfer - TFTP * - FTP - NFS E-Mail - SMTP Remote Login - Telnet * - rlogin Network Management - SNMP * Name Management - DNS*

104. 104 FTP Service · FTP enables a user to transfer files between two networked computers. · FTP also provides a variety of login, directory inspection, file manipulation, and other session control functions. · FTP can be used to move files between disparate local operating systems

105. 105 SMTP Service Simple Mail Transfer Protocol is an electronic mail routing protocol that uses TCP and IP to route mail messages between network hosts.

106. 106 Remote Terminal Emulation allows users to access host-based applications over the network, with personal computers functioning as dumb terminals. Like FTP, TELNET can provide connectivity between dissimilar systems (for example, DOS and UNIX). It has been one of the most widely used network applications. TELNET Service

107. 107 DNS Service The domain name can be up to 255 characters long and is not case-sensitive (each label can have up to 63 characters)

108. 108 172.16.2.2172.16.1.2 172.16.1.1 172.16.2.1 www.sun.com ftp.sun.com DNS Server www.sun.com 172.16.1.2 ftp.sun.com 172.16.2.2 : : : : : : : : : : : : : : : DNS Table DNS Service

109. 109 DNS Service Ask Domain Name: ftp.novell.de

110. 110 The Next Generation Internet Protocol

111. 111 IPv6 (IP version 6) addresses 128-bit addresses Will replace IPv4 Quality-of-Service Capabilities Authentication and Privacy Capabilities IPv6 Only 6% of IPv4 addresses are unassigned

112. 112 Describe how the TCP/IP implementation relates to the OSI reference model The functions of the TCP/IP network-layer protocols IP addresses are specified in 32-bit dotted-decimal format that indicates class, network, and host identifications. Subnet masks are used to indicate the boundary between network, subnet, and host IDs ICMP ARP/RARP Summary

113. 113 The functions of the TCP/IP transport-layer protocols TCP/UDP -- Acknowledged and unacknowledged transports, Port Numbers, Sequence and Reliability Protocols to support file transfer, e-mail, and other applications New Technology Summary