Chapter Three

1
Chapter Three

• Network
• Protocols

2
Chapter Objectives

• Identify the characteristics of TCP/IP, IPX/SPX,
  NetBIOS, and AppleTalk
• Understand the position of network protocols in
  the OSI Model
• Identify the core protocols of each protocol
  suite and its functions
• Understand each protocols addressing scheme
• Install protocols on Windows 95 and Windows NT
  clients

3
Introduction to Protocols

• Protocols
• Rules a network uses to transfer data
• Protocols that can span more than one LAN segment
  are routable
• Multiprotocol Network
• Network using more than one protocol

4
TCP/IP
OSI Model
TCP/IP

• Transmission Control Protocol/Internet Protocol
  (TCP/IP)
• Suite of small, specialized protocols called
  subprotocols

FIGURE 3-1 TCP/IP compared to the OSI Model
5
TCP/IP Versus OSI
6
TCP/IP Compared to theOSI Model

• Application layer roughly corresponds to
  Application and Presentation layers
• Transport layer roughly corresponds to Session
  and Transport layers
• Internet layer is equivalent to the Network layer
• Network Interface layer roughly corresponds to
  Data Link and Physical layers

7
TCP/IP Core Protocols

• Subprotocols of the TCP/IP suite
• In addition to its subprotocols, the TCP/IP suite
  features routing protocols
• Assist routers in efficiently managing
  information flow

8
Internet Protocol (IP)

• Provides information about how and where data
  should be delivered
• Subprotocol enabling TCP/IP to internetwork
• Traverse more than one LAN segment and more than
  one type of network through a router
• Subnets
• The individual networks joined together by
  routers in an internetwork

9
Internet Protocol (IP)

• IP Datagram
• IP portion of a TCP/IP frame that acts as an
  envelope for data
• Contains information necessary for routers to
  transfer data between subnets

FIGURE 3-2 Components of an IP datagram
10
Internet Protocol (IP)

• IP does not guarantee delivery of data
• Connectionless
• Allows the protocol to service a request without
  requesting a verified session and without
  guaranteeing delivery of data

11
Transport Control Protocol (TCP)

• Provides reliable data delivery services
• Connection oriented
• Requires the establishment of a connection
  between communicating nodes before the protocol
  will transmit data
• TCP segment
• Holds the TCP data fields
• Becomes encapsulated by the IP datagram

12
Transport Control Protocol (TCP)

• Port
• Address on host where an application makes itself
  available to incoming data

FIGURE 3-3 A TCP segment
13
Additional Core Protocols of the TCP/IP Suite

• User Datagram Protocol (UDP)
• A connectionless transport service
• Internet Control Message Protocol (ICMP)
• Notifies the sender that something has gone wrong
  in the transmission process and that packets were
  not delivered

14
Additional Core Protocols of the TCP/IP Suite

• Address Resolution Protocol (ARP)
• Obtains the MAC address of a host or node
• Creates a local database mapping the MAC address
  to the hosts IP address

15
TCP/IP Application Layer Protocols

• Telnet is used to log on to remote hosts using
  TCP/IP Protocol
• File Transfer Protocol (FTP) is used to send and
  receive files via TCP/IP
• Simple Mail Transfer Protocol (SMTP) is
  responsible for moving messages from one e-mail
  server to another, using the Internet and other
  TCP/IP-based networks
• Simple Network Management Protocol (SNMP) manages
  devices on a TCP/IP network

16
Addressing in TCP/IP

• IP Address
• Logical address used in TCP/IP networking
• Unique 32-bit number
• Divided into four groups of octets (8-bit bytes)
• Separated by periods

17
Addressing in TCP/IP
TABLE 3-1 Commonly used TCP/IP classes

• Though 8 bits have 256 possible combinations,
  only the numbers 1 through 254 are used to
  identify networks and hosts
• Numbers 0 and 255 are reserved for broadcasts
• Transmissions to all stations on a network

18
Addressing in TCP/IP

• Loopback address
• IP address reserved for communicating from a node
  to itself
• Value of the loopback address is always 127.0.0.1
• InterNIC
• Authority for Internet IP addressing and domain
  name registration
• Also known as Network Solutions

19
Addressing in TCP/IP

• Firewall
• Specialized device
• Selectively filters or blocks traffic between
  networks
• May be strictly hardware-based or may involve a
  combination of hardware and software
• Host
• Computer connected to a network using the TCP/IP
  protocol

20
Addressing in TCP/IP

• In IP address 131.127.3.22, to convert the first
  octet (131) to a binary number
• On Windows 95, click Start, point to Programs,
  point to Accessories, then click Calculator
• Click View, then click Scientific (make sure Dec
  option button is selected)
• Type 131, then click Bin option button
• The binary number 131, 10000011, appears in the
  display window

21
Addressing in TCP/IP

• Static IP address
• IP address manually assigned to a device
• Dynamic Host Configuration Protocol protocol
• Application layer protocol
• Manages the distribution of IP addresses on a
  network

22
Viewing IP Information

• On a Windows 95 workstation connected to a
  network
• Click Start, then click Run
• Type winipcfg
• Click OK
• Click More Info
• Click OK to close window

FIGURE 3-4 Example of an IP configuration window
23
Viewing IP Information

• On a Windows NT workstation
• Click Start, point to Programs, then click MS-DOS
  Prompt
• Type ipconfig/all

FIGURE 3-5 IP address information on a Windows NT
workstation
24
Addresses and Names

• In addition to using IP addresses, TCP/IP
  networks use names for networks and hosts
• Each host requires a host name
• Each network requires a network name, also called
  a domain name
• Symbolic name that identifies and Internet domain

25
IPX/SPX

• Internetwork Packet Exchange/Sequenced Packet
  Exchange (IPX/SPX)
• Protocol originally developed by Xerox
• Modified and adopted by Novell in the 1980s for
  the NetWare network operating system

FIGURE 3-6 IPX/SPX compared to the OSI Model
26
IPX/SPX Core Protocols

• Internetwork Packet Exchange (IPX)
• Provides routing and internetworking services
• Similar to IP in TCP/IP suite

FIGURE 3-7 Components of an IPX datagram
27
IPX/SPX Core Protocols

• Sequence Packet Exchange (SPX)
• Works in tandem with IPX to ensure data are
  received
• Whole
• In sequence
• Error free

28
SPX
FIGURE 3-8 SPX packet encapsulated by an IPX
datagram
29
IPX/SPX Core Protocols

• Service Advertising Protocol (SAP)
• Runs directly over IPX
• Used by NetWare servers and routers to advertise
  to entire network which services they can provide
• NetWare Core Protocol (NCP)
• Handles requests for services between clients and
  servers

30
Addressing in SPX/IPX

• IPX address
• An address assigned to a device on an IPX/SPX
  network
• Contains two parts
• Network address (external network number)
• Node address

31
Viewing the IPX Address

• With Windows 95, Windows 98, or Windows NT
  workstations while connected to Netware server
  running version 4.0 or higher
• Click Start, point to Programs, then click MS-DOS
  Prompt
• Change directories to a drive letter mapped to
  the network
• Type nlist XXXXX /a (with XXXXX being NetWare
  user logon ID)

32
Viewing the IPX Address

• With Windows 95 or Windows NT workstations while
  connected to NetWare server running a version
  lower than 4.0
• Click Start, point to Programs, then click MS-DOS
  Prompt
• Type userlist userXXXXX/a (with XXXXX being
  NetWare logon ID)

33
NetBIOS and NetBEUI

• Network Basic Input Output System (NetBIOS)
• Originally designed by IBM to provide Transport
  and Session layer services
• Adopted by Microsoft as its foundation protocol
• Microsoft added Application layer component
  called NetBIOS Enhanced User Interface (NetBEUI)

34
NetBEUI

• Fast and efficient protocol
• Consumes few network resources
• Provides excellent error correction
• Requires little configuration

35
NetBIOS and NetBEUI Compared to the OSI Model
FIGURE 3-9 NetBIOS/NetBEUI compared to the OSI
Model
36
NetBIOS Addressing

• Viewing a workstations NetBIOS name
• Right-click the Network Neighborhood icon, then
  click Properties
• Click the Identification tab

FIGURE 3-10 Identification tab in Network
properties
37
AppleTalk

• Protocol suite used to interconnect Macintosh
  computers
• Originally designed to support peer-to-peer
  networking among Macintoshes
• Can now be routed between network segments and
  integrated with NetWare- and Microsoft-based
  networks

38
AppleTalk

• AppleTalk zone
• Logical groups of computers defined on an
  AppleTalk network
• Enables users to share file and print services

FIGURE 3-11 AppleTalk protocol compared to OSI
Model
39
AppleTalk Subprotocols

• AppleShare
• AppleTalk Filing Protocol (AFP)
• AppleTalk Session Protocol (ASP)
• AppleTalk Transaction Protocol (ATP)

40
AppleTalk Subprotocols

• Name Binding Protocol (NBP)
• Routing Table Maintenance Protocol (RTMP)
• Zone Information Protocol (ZIP)
• Datagram Delivery Protocol (DDP)

41
Addressing in AppleTalk

• AppleTalk node ID
• Unique 8-bit or 16-bit number identifying a
  computer on an AppleTalk network
• AppleTalk network number
• Unique 16-bit number identifying the network to
  which an AppleTalk node is connected

42
Installing Protocols

• After installing protocols, they must be binded
• Binding
• Process of assigning one network component to
  work with another

43
Installing Protocols on a Windows NT Workstation

• Insert Windows NT installation CD-ROM
• Log on to the workstation as an Administrator
• Right-click the Network Neighborhood icon, then
  click Properties
• Click Protocols tab
• Click Add
• In list of network protocols, click NWLink
  IPX/SPX Compatible Transport, then click OK
• Type the appropriate path to the installation
  files, then click Continue

44
Installing Protocols on a Windows NT Workstation

• Click OK
• Click Yes to restart your workstation
• Verify protocol was installed by again logging to
  workstation as an Administrator
• Right-click the Network Neighborhood icon, then
  click Properties
• Click the Protocols tab
• Verify NWLink (IPX/SPX) Protocol appears in list
  of installed protocols
• Click Cancel to close dialog box

45
Installing Protocols on a Windows 95 Workstation

• Right-click Network Neighborhood icon, then click
  Properties
• Verify Configuration tab is selected
• Click Add
• Double-click Protocol
• In the list of manufacturers, click Microsoft
• In list of protocols, click TCP/IP

46
Installing Protocols on a Windows 95 Workstation

• Click OK
• If TCP/IP is not already installed on
  workstation, follow prompt and click Yes to
  restart your computer
• Verify protocol was installed by right-clicking
  Network Neighborhood icon, then click Properties
• Verify Configuration tab is selected
• Click Cancel to close window

47
Chapter Summary

• Protocols define the standards for communication
  between nodes on a network
• Protocols vary in speed, transmission efficiency,
  utilization of resources, ease of setup,
  compatibility, and ability to travel between one
  LAN segment or another
• TCP/IP is fast becoming most popular network
  protocol
• TCP/IP suite of protocols can be divided into
  four layers roughly corresponding to the seven
  layers of the OSI Model

48
Chapter Summary

• Operating in Transport or Network layers of OSI
  Model, TCP/IP core protocols provide
  communications between hosts on a network
• Internet Protocol (IP) provides information about
  how and where data should be delivered
• Transport Control Protocol (TCP) provides
  reliable data delivery services
• User Datagram Protocol (UDP) is a connectionless
  transport service
• Internet Control Message Protocol (ICMP) notifies
  the sender that something has gone wrong in the
  transmission process and that packets were not
  delivered

49
Chapter Summary

• Address Resolution Protocol (ARP) obtains the MAC
  address of a host or node then Creates a local
  database mapping the MAC address to the hosts IP
  address
• Each IP address is a unique 32-bit number,
  divided into four groups of octets separated by
  periods
• Range of addresses beginning with 127 is reserved
  for loopback information
• Every host on a network must have a unique number
• Internetworking Packet Exchange/Sequenced Packet
  Exchange (IPE/SPE) is a protocol originally
  developed by Xerox then modified and adopted by
  Novell in the 1980s for its NetWare NOS

50
Chapter Summary

• Core protocols of IPX/SPX provide services at
  Transport and Network layers of OSI Model
• Internet Packet Exchange provides routing and
  internetwork services similar to IP in TCP/IP
  suite
• Sequence Packet Exchange (SPX) works in tandem
  with IPX to ensure data are received whole, in
  sequence, and error free
• Service Advertising Protocol (SAP) is used by
  NetWare servers and routers to advertise to
  entire network which services they can provide
• NetWare Control Protocol (NCP) handles requests
  for services between clients and servers

51
Chapter Summary

• Addresses on an IPX/SPX network are called IPX
  addresses
• Network Basic Input Output System (NetBIOS) was
  originally developed by IBM to provide Transport
  and Session layer services
• Microsoft adopted NetBIOS as its foundation
  protocol, then added an Application layer
  component called NetBIOS Enhanced User Interface
  (NetBEUI)
• To transmit data between network nodes, NetBIOS
  needs to know how to reach each workstation
• AppleTalk is the the protocol suite used to
  interconnect Macintosh computers

52
Chapter Summary

• An AppleTalk network is separated into logical
  groups of computers called AppleTalk zones
• Though Apple has improved AppleTalks ability to
  use different network models and span network
  segments, it remains unsuited to large LANs or
  WANs
• In addition to zone names, AppleTalk uses node
  Ids and network numbers to identify computers on
  a network
• Though some protocolssuch as NetBIOSrequire no
  configuration after installation, otherssuch as
  TCP/IPdo require configuration