LOCAL AREA NETWORKS. Patrick Regan. Institute of Technology. PEARSON Prentice Hall. Upper Saddle River, New Jersey Columbus, Ohio

Transcription

1 LOCAL AREA NETWORKS Patrick Regan Institute of Technology PEARSON Prentice Hall Upper Saddle River, New Jersey Columbus, Ohio

2 PARTI BUILDING A NETWORK 1 CHAPTER 1I Introduction to Networks NETWORK BEGINNINGS DEFINITION OF NETWORK Network Services Network Media Protocols NETWORK CHARACTERISTICS Servers, Clients, and Peers Server's Roles LANs, MANs, and WANs NETWORK SOFTWARE Windows NT Family UNIX Linux Novell NetWare OS/ Apple Macintosh Computers INTRODUCTION TO TROUBLESHOOTING Computer Problem Network Problem General Troubleshooting Strategy Where to Get Help 19 CHAPTER / Introduction to the OSI Model 24 Jmm 2.1 THE NEED FOR STANDARDIZATION OSI REFERENCE MODEL BITS AND BYTES Binary Number System Hexadecimal Number System ASCII Character Set 38 VII

3 viii Contents 2.4 PHYSICAL LAYER Signaling Synchronous and Asynchronous Connections Bandwidth Point-to-Point and Multipoint Connections DATA LINK LAYER Physical Device Addressing Media Access Methods THE 802 PROJECT MODEL NETWORK LAYER Network Addressing Data-Switching Techniques Routing Protocols TRANSPORT LAYER Connection Services Error Control Flow Control Multiplexing and Demultiplexing SESSION LAYER PRESENTATION LAYER APPLICATION LAYER CONNECTIVITY DEVICES Network Cards and Cables Repeaters Hubs and MAUs Bridge and Switching Hub Routers and Brouters Gateway 65 CHAPTER & Media and Topologies 74 **" 3.1 DATA AND THE NETWORK TOPOLOGIES Physical Topology Logical Topology Segment and Backbone CABLING Unshielded Twisted Pair Building UTP Cable Shielded Twisted Pair Coaxial Cable Building a Coaxial Cable Screened Twisted Pair 99

4 ix Fiber Optics CABLE MANAGEMENT The EIA 568-A Wiring Standard Plenum Wall Jacks Punch-Down Block Patch Panel Cable Ties, Basket Systems, and Management Racks Server Rooms TESTING CABLE SYSTEMS Network Card Diagnostics Crossover Cable Voltmeter and Ohmmeter Cable Testers Tone Generators Time Domain Reflectometers Visual Fault Locators Fiber-Optic Power Meters Optica Time Domain Reflectometers Fiber-Optic Inspection Microscopes Multifunction Cable Scanners WIRELESS LAN Radio Systems Microwave Signals Infrared Systems Wireless LAN Configurations NETWORK CARDS Characteristics of a Network Card MAC Address Installing a Network Card Diskless Workstations HUBS Types of Hubs Parts of the Hub Installing a Hub BRIDGES Basic Bridges Transparent Bridge Spanning Tree Algorithm Source-Route Bridging SWITCHES VLANs ROUTERS 135

5 3.13 ROUTING PROTOCOLS Static versus Dynamic Routes Distance-Vector versus Link-State Algorithm Count to Infinity 138 CHAPTER /I Networking Technologies ETHERNET Ethernet Encoding Method Ethernet Frame Types Base5 (Thicknet) Base2(Thinnet) BaseT(Twisted-Pair Ethernet) MBPS Ethernet Gigabit Ethernet Rule PLANNING AN ETHERNET NETWORK TOKEN RING LOCALTALK WIRELESS STANDARD Physical Layer and Architecture Framing Medium Access Control Protocol Security BLUETOOTH 168 CHAPTER «% WAN and Remote Access Technologies WAN DEVICES PUBLIC SWITCHED TELEPHONE NETWORK DIAL-UP TECHNOLOGY TheUART Analog Modems Integrated Services Digital Network Traditional Remote Access Remote Authentication Dial-in User Service SLIP and PPP Authentication Protocols PPPOE DIGITAL SUBSCRIBER LINE CABLE MODEMS LEASED DIGITAL LINES FRAME RELAY 204

6 xi 5.8 FDDI SYNCHRONOUS DIGITAL HIERARCHY AND SYNCHRONOUS OPTICAL NETWORK Building Blocks of SDH and SONET SDH and SONET Lines and Rings CELL RELAY Switched Multimegabit Data Service Introduction to ATM USING ROUTERS WITH WAN LINKS VIRTUAL PRIVATE NETWORKING TERMINAL EMULATION INDEPENDENT COMPUTING ARCHITECTURE PROTOCOL 214 PART II PROTOCOLS CHAPTER f\ TCP/IP TCP/IP AND THE INTERNET TCP/IP SUITE IPv4 ADDRESSING SUBNETTING THE NETWORK VARIABLE LENGTH SUBNET MASK AND CLASSLESS INTER- DOMAIN ROUTING IPv TCP/IP PORTS AND SOCKETS ROUTING IN TCP/IP Routing Information Protocol OSPF Other Routing Protocols NETWORKING ADDRESS TRANSLATION AND PROXY SERVERS ARP AND MAC ADDRESS RESOLUTION NAVIGATING A TCP/IP NETWORK TROUBLESHOOTING A TCP/IP NETWORK The Ping Command The Tracert Command The ARP Utility The Netstat Utility The nslookup Utility The nbtstat Utility 266

7 xii Contents CHAPTER / IPX, NetBIOS, and AppleTalk Protocols IPX PROTOCOL SUITE IPXandSPX SAP and NCP Protocols IPX Addressing Frame Types Routing in IPX Protocol Troubleshooting IPX Networks NETBIOS AND NETBEUI SMB Protocol Common Internet File System Accessing a SMB/CIFS Share Name Resolution with the NetBIOS Protocol NetBEUI Protocol APPLETALK AppleTalk Subprotocols AppleTalk Addressing DLC PROTOCOL 288 CHAPTER 8X Network Services INTRODUCTION TO DOMAIN NAME SYSTEM NAME RESOLUTION Domain Name Space DNS Zones Name Resolution Reverse Queries Dynamic DNS Troubleshooting Name Resolution INTRODUCTION TO WINDOWS INTERNET NAME SERVICE Using a WINS Server WINS Clients WINS Server Replication WINS Proxy Agent INTRODUCTION TO DHCP SERVICES The DHCP Requests DHCP Relay Agent SIMPLE NETWORK MANAGEMENT PROTOCOL INTRODUCTION TO WEB PAGES AND WEB SERVERS INTRODUCTION TO HTML LANGUAGE The Head The Body Adding Hyperlinks 321

8 XIII CHAPTER Adding Pictures to Your Web Page Forms and Common Gateway Interface Dynamic HTML and Active Server Pages Extensible Markup Language ActiveX, VBScript, and JavaScript Web Page Editors WebServers HTTP Error Codes 326 OVERVIEW and the Internet Simple Mail Transfer Protocol MIME Retrieving Messaging Application Programming Interface X FILE AND PRINT SHARING 336 Protocol Analyzers PROTOCOL ANALYZERS Placement of Protocol Analyzers Using Microsoft's Network Monitor Looking at a Packet Troubleshooting Ethernet Problems Broadcasts Troubleshooting TCP/IP Problems Using 1CMP Packets to Troubleshoot Analyzing Security Issues 359 \ CHAPTER 10 PART III NETWORK OPERATING SYSTEMS 363 Networking with Windows WHAT IS WINDOWS? WINDOWS NT FAMILY ARCHITECTURE User Mode Kernel Mode WINDOWS FILE AND DISK SYSTEMS FAT FAT NTFS CDFS Volumes Disk Management Tools 376

9 xiv Contents 10.4 WINDOWS NT FAMILY NETWORK ARCHITECTURE WORKGROUPS WINDOWS NT DOMAIN ACTIVE DIRECTORY Organizational Units Objects Forests Planning Your Domain Structure Domain Controllers and Sites USER, GROUP, AND COMPUTER ACCOUNTS User Accounts Built-in User Accounts Home Directories User Profiles Groups Global and Domain Local Group Scopes Universal Groups Computer Accounts POLICIES RIGHTS AND PERMISSIONS NTFS PERMISSIONS NETWORK SERVICES Client Software Network Card Drivers TCP/IP Windows IPCONFIG and WINIPCFG Programs Other Network Protocols SHARING DRIVES, DIRECTORIES, AND PRINTERS Sharing Drives and Directories User and Share Security Models Share Permissions Home Directories Permissions Sharing Printers Browsing the Network Internet Information Services EVENT VIEWER 417 t "i CHAPTER I I Networking with Novell NetWare WHAT IS NETWARE? STARTING AND STOPPING NETWARE NETWARE ARCHITECTURE 440

10 xv 11.4 NETWARE DISK STRUCTURE NOVELL DIRECTORY SERVICES The NDS Tree Structure Naming of Objects The Admin Trustees NDS Design Interacting between Windows and NetWare DIRECTORY AND FILE RIGHTS NETWARE CLIENT SOFTWARE TROUBLESHOOTING WITH NETWARE 453 CHAPTER j \/ Networking with Linux WHAT IS LINUX? Linux Minimum Requirements Linux Kernel Linux Interfaces Network Programs Linux Documentation Project STARTING AND SHUTTING DOWN LINUX FILE SYSTEMS Disk Names in Linux 480» Linux File System 481 ' Mount Points Second Extended File System Journaling File Systems Virtual File System The /proc and /dev File System RUN LEVELS Daemons Starting, Stopping, and Restarting Daemons USER ACCOUNTS User Names Passwords The/etc/passwd File Shadow Passwords Home Directories The Root Account Creating, Modifying, and Deleting Users GROUPS CENTRALIZED AUTHENTICATION USING NIS 503

11 xvi Contents 12.8 FILE SECURITY File Access Codes Setting Default Permissions GROUP STRATEGIES User Private Group Project Groups Multiple-Group Membership CONFIGURING THE NETWORK CONNECTION IN LINUX Configuring the Network Device ifconfig Communicating with Other Networks Troubleshooting TCP/IP Commands NETWORK FILE SYSTEM Configuring an NFS Server Mounting an NFS Drive or Directory SAMBA SWAT Accessing a Samba Share Using smbpasswd vi TEXT EDITOR 530 PART IV MAINTAINING A NETWORK 555 CHAPTER t Network Security SECURITY RISKS ACCOUNT SECURITY User Name Policy Password Policies User Management Rights and Permissions PHYSICAL SECURITY FIREWALLS AND PROXY SERVERS Packet Filters Firewalls Demilitarized Zone Static and Dynamic Packet Filters Circuit-level Gateway Application Gateway Proxy Server Configuring a Browser through a Proxy Server Advanced Firewall Features Personal Firewalls 572

12 xvii 13.5 DENIAL OF SERVICE ENCRYPTION AND DECRYPTION Private-Key Encryption Public-Key Encryption Digital Envelopes, Signatures, and Certificates Hash Encryption RSA and Data Encryption Standards X.509 Certificates SECURITY PROTOCOLS NTLM Authentication Kerberos Authentication SSLandS-HTTP Security Protocols for Virtual Tunnels IPSec DoD SECURITY STANDARDS AUDITING AND INTRUDER DETECTION PENETRATION TESTING Reconnaissance Scanning Vulnerability Testing PATCHES 590 CHAPTER j / Disaster Prevention and Recovery FAULT TOLERANCE AND DISASTER RECOVERY NEEDS RAID REDUNDANT NETWORK CARDS AND HUBS OVERCOMING POWER PROBLEMS Power Irregularities Noise Power Protection Devices Redundant Power Supplies CLUSTERING PLANNING DISASTER RECOVERY TAPE DRIVES The Tape Media Recording Methods Tape Standards BACKUP VIRUSES Types of Viruses Worms Virus Hoaxes Antivirus Software 622

13 xviii Contents Protecting against Viruses Removing a Virus SERVER PERFORMANCE Processor Performance Memory Performance Disk System Performance Network Performance 626 Appendix A: Introduction to the Macintosh OS 631 Appendix B: Answers to Odd-Numbered Questions 635 Glossary 641 Index 675