1 Introduction to TCP/IP

2 Agenda What Is TCP/IP? IP Addressing

3 What Is TCP/IP? A suite of protocols Rules that dictate how packets of information are sent across multiple networks Addressing Error checking

4 IP Internet Protocol (IP) Determines where packets are routed based on their destination addresses Breaks packets into smaller packets and reassembles them

5 TCP/IP Applications Application layer File Transfer Protocol (FTP) Remote Login (Telnet) (SMTP) Transport layer Transport Control Protocol (TCP) User Datagram Protocol (UDP) Network layer Internet Protocol (IP) Data link & physical layer LAN Ethernet, Token Ring, FDDI, etc. WAN Serial lines, Frame Relay, X.25, etc.

6 TCP/IP Transport Layer 21 FTP—File Transfer Protocol 23 Telnet 25 SMTP—Simple Mail Transfer Protocol 37 Time 69 TFTP—Trivial File Transfer Protocol 79 Finger 103 X SNMP—Simple Network Management Protocol 162 SNMPTRAP

7 TCP Transmission Control Protocol

8 UDP User Datagram Protocol Unreliable Fast Assumes application will retransmit on error Often used in diskless workstations

9 ICMP Ping

10 IPv4 Addressing 32-bit addresses Commonly expressed in dotted decimal format (e.g., ) Each “dotted decimal” is commonly called an octet (8 bits)

11 IP Addressing—Three Classes Class A: NET.HOST.HOST.HOST Class B: NET.NET.HOST.HOST Class C: NET.NET.NET.HOST

12 IP Addressing—Class A Network # 10 Host # Range of class A network IDs: 1–126 Number of available hosts: 16,777,214

13 IP Addressing—Class B Network # Host # Range of class B network IDs: 128.1– Number of available hosts: 65,534

14 IP Addressing—Class C Network # Host # 1 Range of class C network IDs: – Number of available hosts: 254

15 IP Network Address Classes # Networks ,384 2,097,152 # Hosts ,534 16,777,214 Class A B C Class A Class B Class C Network Address Space Host Address Space Example

16 IP Subnetting Subnets allow routing by ranges

17 IP Subnet Mask Given: Address = Subnet Mask = Subnet =

18 IP Address Assignment ISPs assign addresses to customers IANA assigns addresses to ISPs CIDR block: bundle of addresses

19 Summary TCP/IP is a suite of protocols TCP/IP defines communications between computers on the Internet IP determines where packets are routed based on their destination address TCP ensures packets arrive correctly at their destination address