Front cover TCP/IP Tutorial and Technical Overview Understand networking fundamentals of the TCP/IP protocol suite Introduces advanced concepts and new technologies Includes the latest TCP/IP protocols Lydia Parziale David T. Britt Chuck Davis Jason Forrester Wei Liu Carolyn Matthews Nicolas Rosselot ibm.com/redbooks International Technical Support Organization TCP/IP Tutorial and Technical Overview December 2006 GG24-3376-07 Note: Before using this information and the product it supports, read the information in “Notices” on page xvii. Eighth Edition (December 2006) © Copyright International Business Machines Corporation 1989-2006. All rights reserved. Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Notices . xvii Trademarks . xviii Preface . xix The team that wrote this redbook. xx Become a published author . xxii Comments welcome. xxiii Part 1. Core TCP/IP protocols . 1 Chapter 1. Architecture, history, standards, and trends . 3 1.1 TCP/IP architectural model . 4 1.1.1 Internetworking . 4 1.1.2 The TCP/IP protocol layers . 6 1.1.3 TCP/IP applications. 9 1.2 The roots of the Internet . 12 1.2.1 ARPANET . 14 1.2.2 NSFNET . 15 1.2.3 Commercial use of the Internet . 16 1.2.4 Internet2 . 18 1.2.5 The Open Systems Interconnection (OSI) Reference Model . 20 1.3 TCP/IP standards . 21 1.3.1 Request for Comments (RFC) . 22 1.3.2 Internet standards . 24 1.4 Future of the Internet. 26 1.4.1 Multimedia applications. 26 1.4.2 Commercial use . 26 1.4.3 The wireless Internet. 27 1.5 RFCs relevant to this chapter . 27 Chapter 2. Network interfaces . 29 2.1 Ethernet and IEEE 802 local area networks (LANs) . 30 2.1.1 Gigabit Ethernet . 33 2.2 Fiber Distributed Data Interface (FDDI). 33 2.3 Serial Line IP (SLIP) . 34 2.4 Point-to-Point Protocol (PPP) . 35 2.4.1 Point-to-point encapsulation . 37 2.5 Integrated Services Digital Network (ISDN) . 38 2.6 X.25 . 39 © Copyright IBM Corp. 1989-2006. All rights reserved. iii 2.7 Frame relay . 41 2.7.1 Frame format. 41 2.7.2 Interconnect issues . 43 2.7.3 Data link layer parameter negotiation . 43 2.7.4 IP over frame relay . 44 2.8 PPP over SONET and SDH circuits . 45 2.8.1 Physical layer . 46 2.9 Multi-Path Channel+ (MPC+) . 46 2.10 Asynchronous transfer mode (ATM) . 47 2.10.1 Address resolution (ATMARP and InATMARP) . 47 2.10.2 Classical IP over ATM. 50 2.10.3 ATM LAN emulation . 56 2.10.4 Classical IP over ATM versus LAN emulation. 59 2.11 Multiprotocol over ATM (MPOA) . 60 2.11.1 Benefits of MPOA . 60 2.11.2 MPOA logical components . 61 2.11.3 MPOA functional components. 62 2.11.4 MPOA operation . 63 2.12 RFCs relevant to this chapter . 64 Chapter 3. Internetworking protocols . 67 3.1 Internet Protocol (IP) . 68 3.1.1 IP addressing . 68 3.1.2 IP subnets . 72 3.1.3 IP routing. 77 3.1.4 Methods of delivery: Unicast, broadcast, multicast, and anycast . 84 3.1.5 The IP address exhaustion problem . 86 3.1.6 Intranets: Private IP addresses . 89 3.1.7 Network Address Translation (NAT) . 89 3.1.8 Classless Inter-Domain Routing (CIDR) . 95 3.1.9 IP datagram. 98 3.2 Internet Control Message Protocol (ICMP) . 109 3.2.1 ICMP messages . 110 3.2.2 ICMP applications . 117 3.3 Internet Group Management Protocol (IGMP) . 119 3.4 Address Resolution Protocol (ARP) . 119 3.4.1 ARP overview . 119 3.4.2 ARP detailed concept . 120 3.4.3 ARP and subnets . 123 3.4.4 Proxy-ARP or transparent subnetting . 123 3.5 Reverse Address Resolution Protocol (RARP) . 124 3.5.1 RARP concept. 125 3.6 Bootstrap Protocol (BOOTP). 125 iv TCP/IP Tutorial and Technical Overview 3.6.1 BOOTP forwarding . 129 3.6.2 BOOTP considerations . 130 3.7 Dynamic Host Configuration Protocol (DHCP) . 130 3.7.1 The DHCP message format . 132 3.7.2 DHCP message types. 134 3.7.3 Allocating a new network address. 134 3.7.4 DHCP lease renewal process . 137 3.7.5 Reusing a previously allocated network address . 138 3.7.6 Configuration parameters repository. 139 3.7.7 DHCP considerations . 139 3.7.8 BOOTP and DHCP interoperability . 140 3.8 RFCs relevant to this chapter . 140 Chapter 4. Transport layer protocols. ..