70-291: MCSE Guide to Managing a Microsoft Windows Server 2003 Network Chapter 3: TCP/IP Architecture

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network2 Objectives Describe the overall architecture of TCP/IP Identify application layer protocols in the TCP/IP protocol suite Compare and contrast TCP/IP and UDP transport layer protocols Understand the role of various Internet layer protocols including IP, ICMP, and ARP Describe different network layer interface protocols

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network3 TCP/IP Architecture Overview TCP/IP varies slightly from the standard OSI model Represented by a four-layer model Layers include: Application Transport Internet Network Interface

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network4 TCP/IP Architecture Overview (continued)

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network5 TCP/IP Architecture Overview (continued) Application layer provides access to network resources Transport layer is responsible for preparing data to be sent over the network Internet layer is responsible for logical addressing and routing Network Interface layer consists of the network card driver and the network card circuitry itself

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network6 Application Layer Protocols Application layer accepts data from software and sends it to the network There are many application layer protocols that are only available on TCP/IP networks Each of these protocols is associated with a client application and service

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network7 HTTP Hypertext Transfer Protocol Most common protocol used on the Internet today Used by Web browsers and Web servers HTTP defines the commands that Web browsers can send and how Web servers are capable of responding CGI, ISAPI, and NSAPI can be used to pass data from a Web server to an application

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network8 FTP File Transfer Protocol Simple file-sharing protocol Slowly becoming obsolete as HTTP can be used for downloading/uploading files Protocol first introduced in the 1980s for UNIX systems

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network9 Telnet Terminal emulation program Primarily used to connect remotely to UNIX and Linux machines Does not support a graphical user interface Many telnet clients can be connected to a server concurrently Useful for administering UNIX and Linux systems

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network10 SMTP Simple Mail Transfer Protocol Used to send and receive messages between e- mail servers Protocol also used by client software such as Microsoft Outlook

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network11 POP3 Post Office Protocol version 3 Most commonly used protocol for reading messages Has commands to download and delete messages from servers Does not support the sending of messages POP3 supports only a single inbox Does not support multiple folders for storage on the server

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network12 IMAP4 Internet Message Access Protocol version 4 Another protocol used to read messages Has abilities beyond those of POP3 Can download message headers only Allows multiple folders on the server side

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network13 Transport Layer Protocols These protocols are responsible for preparing data to be sent over the network The most common task is to break information up into packets Each transport layer protocol has its own set of ports An IP address and port number collectively form a socket The port number ensures that a packet is delivered to the correct service

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network14 Transport Layer Protocols (continued)

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network15 TCP Transmission Control Protocol is the most commonly used transport layer protocol Connection oriented – a connection must be established before data is transferred between computers Connection is established using a three-way handshake TCP tracks each packet to ensure it was successfully delivered Packets are delivered using a sliding window

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network16 UDP User Datagram Protocol Not as common as TCP/IP UDP is connectionless and unreliable Streaming audio and video use this protocol Resolution of a DNS name is done via UDP

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network17 TCP versus UDP TCP is connection-oriented and reliable UDP is connectionless and unreliable

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network18 Internet Layer Protocols Responsible for all tasks related to logical addressing An IP address is a logical address Protocols in this layer include: IP, RIP, OSPF, ICMP, IGMP, and ARP Protocols in this layer are aware of other networks

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network19 IP Internet Protocol is responsible for the logical addressing of each packet created by the Transport layer As each packet is sent out, IP attaches the source and destination address to the packet IP verifies that, once the machine receives a packet over the network, that packet has the same destination address as the IP address of the computer

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network20 RIP and OSPF Routing Information Protocol and Open Shortest Path First Both are routing protocols Responsible for defining how paths are chosen through the internetwork from one computer to another Define how routers can share information about the networks of which they are aware

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network21 ICMP Internet Control Messaging Protocol Used to send IP error and control messages between routers and hosts Most common use is the ping utility Ping is used to help determine if a computer is functional and able to communicate over the network Internet Assigned Numbers Authority maintains a complete list of ICMP packet types

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network22 ICMP (continued)

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network23 IGMP Internet Group Management Protocol Used for the management of multicast groups Hosts use IGMP to inform routers of their membership in multicast groups Routers use IGMP to announce that their networks have members in particular multicast groups IGMP allows multicast packets to be distributed only to routers that have interested hosts connected

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network24 ARP Address Resolution Protocol Used to convert logical IP addresses to physical MAC addresses Network cards use a MAC address to filter irrelevant packets Data packets have four addresses: source IP address, destination IP address, source MAC address, and destination MAC address ARP uses a two-packet process to find the MAC address of the destination computer

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network25 ARP (continued)

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network26 ARP (continued) ARP request First packet Broadcast to all computers on a local network, asking for the MAC address of the computer with the destination IP address Destination computer sees this packet and replies with the address The communication process then proceeds

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network27 ARP (continued)

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network28 ARP (continued)

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network29 ARP (continued)

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network30 Network Interface Layer Protocols Most of the common Network Interface layer protocols are defined by IEEE Ethernet is the most common Network Interface layer protocol used in corporate networks today All varieties of Ethernet use Carrier Sense Multiple Access/Collision Detection for access control

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network31 Network Interface Layer Protocols (continued)

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network32 Network Interface Layer Protocols (continued)

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network33 Network Interface Layer Protocols (continued) Token Ring is an older technology created by IBM Token Ring was commonly implemented with mainframe computers Wireless LAN is one of the fastest growing network types b defines the most common wireless standard Bluetooth is a short-range wireless communications system

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network34 Summary The TCP/IP model is composed of four layers: Application, Transport, Internet, and Network Interface Many Application layer protocols, each of which is associated with a client application and service HTTP: most common protocol used on the Internet FTP is used for transferring files across the Internet Telnet: remote connect to UNIX and Linux systems

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network35 Summary (continued) SMTP is used to send and receive messages between servers POP3: most common protocol used for reading e- mail messages IMAP4: another protocol used for reading The two Transport layer protocols are TCP and UDP TCP is connection-oriented and reliable UDP is connectionless and unreliable

70-291: MCSE Guide to Managing a Microsoft WIndows Server Network36 Summary (continued) Internet layer protocols: Responsible for tasks related to logical addressing All very specialized IP, RIP, OSPF, ICMP, IGMP, and ARP Ethernet: most common Network Interface layer protocol used in corporate networks today Wireless LANs are one of the fastest growing network types