1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Preface</title><link rel="stylesheet" href="samba.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.66.1"><link rel="start" href="index.html" title="Samba-3 by Example"><link rel="up" href="index.html" title="Samba-3 by Example"><link rel="prev" href="pr03.html" title="Foreword"><link rel="next" href="primer.html" title="Chapter�1.�Networking Primer"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Preface</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="pr03.html">Prev</a>�</td><th width="60%" align="center">�</th><td width="20%" align="right">�<a accesskey="n" href="primer.html">Next</a></td></tr></table><hr></div><div class="preface" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="preface"></a>Preface</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="preface.html#id2464650">Why Is This Book Necessary?</a></span></dt><dd><dl><dt><span class="sect2"><a href="preface.html#id2464037">Samba 3.0.12 Update Edition</a></span></dt></dl></dd><dt><span class="sect1"><a href="preface.html#id2464969">Prerequisites</a></span></dt><dt><span class="sect1"><a href="preface.html#id2465001">Approach</a></span></dt><dt><span class="sect1"><a href="preface.html#id2465066">Summary of Topics</a></span></dt><dt><span class="sect1"><a href="preface.html#id2463725">Conventions Used</a></span></dt></dl></div><p> 2 Network administrators live busy lives. We face distractions and pressures 3 that drive us to seek proven, working case scenarios that can be easily 4 implemented. Often this approach lands us in trouble. There is a 5 saying that, geometrically speaking, the shortest distance between two 6 points is a straight line, but practically we find that the quickest 7 route to a stable network solution is the long way around. 8 </p><p> 9 This book is your means to the straight path. It provides step-by-step, 10 proven, working examples of Samba deployments. If you want to deploy 11 Samba-3 with the least effort, or if you want to become an expert at deploying 12 Samba-3 without having to search through lots of documentation, this 13 book is the ticket to your destination. 14 </p><p> 15 Samba is software that can be run on a platform other than Microsoft Windows, 16 for example, UNIX, Linux, IBM System 390, OpenVMS, and other operating systems. 17 Samba uses the TCP/IP protocol that is installed on the host server. When 18 correctly configured, it allows that host to interact with a Microsoft Windows 19 client or server as if it is a Windows file and print server. This book 20 will help you to implement Windows-compatible file and print services. 21 </p><p> 22 The examples presented in this book are typical of various businesses and 23 reflect the problems and challenges they face. Care has been taken to preserve 24 attitudes, perceptions, practices, and demands from real network case studies. 25 The maximum benefit may be obtained from this book by working carefully through 26 each exercise. You may be in a hurry to satisfy a specific need, so feel 27 free to locate the example that most closely matches your need, copy it, and 28 innovate as much as you like. Above all, enjoy the process of learning the 29 secrets of MS Windows networking that is truly liberated by Samba. 30 </p><p> 31 The focus of attention in this book is Samba-3. Specific notes are made in 32 respect of how Samba may be made secure. This book does not attempt to provide 33 detailed information regarding secure operation and configuration of peripheral 34 services and applications such as OpenLDAP, DNS and DHCP, the need for which 35 can be met from other resources that are dedicated to the subject. 36 </p><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2464650"></a>Why Is This Book Necessary?</h2></div></div></div><p> 37 This book is the result of observations and feedback. The feedback from 38 the Samba-HOWTO-Collection has been positive and complimentary. There 39 have been requests for far more worked examples, a 40 “<span class="quote"><span class="emphasis"><em>Samba Cookbook,</em></span></span>” and for training materials to 41 help kick-start the process of mastering Samba. 42 </p><p> 43 The Samba mailing list's users have asked for sample configuration files 44 that work. It is natural to question one's own ability to correctly 45 configure a complex tool such as Samba until a minimum necessary 46 knowledge level has been attained. 47 </p><p> 48 The Samba-HOWTO-Collection, as do <span class="emphasis"><em>The Official Samba-3 HOWTO and 49 Reference Guide</em></span>, document Samba features and functionality in 50 a topical context. This book takes a completely different approach. It 51 walks through Samba network configurations that are working within particular 52 environmental contexts, providing documented step-by-step implementations. 53 All example case configuration files, scripts, and other tools are provided 54 on the CD-ROM. This book is descriptive, provides detailed diagrams, and 55 makes deployment of Samba-3 a breeze. 56 </p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2464037"></a>Samba 3.0.12 Update Edition</h3></div></div></div><p> 57 The Samba 3.0.x series has been remarkably popular. At the time this book first 58 went to print samba-3.0.2 was being released. There have been significant modifications 59 and enhancements between samba-3.0.2 and samba-3.0.11 (the current release) that 60 necessitate this documentation update. This update has the specific intent to 61 refocus this book so that its guidance can be followed for samba-3.0.12 62 and beyond. Further changes are expected as Samba-3 matures further and will 63 be reflected in future updates. 64 </p><p> 65 The changes shown in <a href="preface.html#pref-new" title="Table�1.�Samba Changes 3.0.2 to 3.0.12">???</a> are incorporated in this update: 66 </p><div class="table"><a name="pref-new"></a><p class="title"><b>Table�1.�Samba Changes 3.0.2 to 3.0.12</b></p><table summary="Samba Changes 3.0.2 to 3.0.12" border="1"><colgroup><col align="left"><col align="justify"></colgroup><thead><tr><th align="left"> 67 <p> 68 New Feature 69 </p> 70 </th><th align="left"> 71 <p> 72 Description 73 </p> 74 </th></tr></thead><tbody><tr><td align="left"> 75 <p> 76 Winbind Case Handling 77 </p> 78 </td><td align="justify"> 79 <p> 80 User and group names returned by <span><b class="command">winbindd</b></span> are now converted to lower case 81 for better consistency. Samba implementations that depend on the case of information returned 82 by winbind (such as %u and %U) must now convert the dependency to expecting lower case values. 83 This affects mail spool files, home directories, valid user lines in the <tt class="filename">smb.conf</tt> file, etc. 84 </p> 85 </td></tr><tr><td align="left"> 86 <p> 87 Schema Changes 88 </p> 89 </td><td align="justify"> 90 <p> 91 Addition of code to handle password aging, password uniqueness controls, bad 92 password instances at logon time, have made necessary extensions to the SambaSAM 93 schema. This change affects all sites that use LDAP and means that the directory 94 schema must be updated. 95 </p> 96 </td></tr><tr><td align="left"> 97 <p> 98 Username Map Handling 99 </p> 100 </td><td align="justify"> 101 <p> 102 Samba-3.0.8 redefined the behavior: Local authentication results in a username map file 103 lookup before authenticating the connection. All authentication via an external domain 104 controller will result in the use of the fully qualified name (i.e.: DOMAIN\username) 105 after the user has been successfully authenticated. 106 </p> 107 </td></tr><tr><td align="left"> 108 <p> 109 UNIX extension handling 110 </p> 111 </td><td align="justify"> 112 <p> 113 Symbolicly linked files and directories on the UNIX host to absolute paths will 114 now be followed. This can be turned off using “<span class="quote"><span class="emphasis"><em>wide links = No</em></span></span>” in 115 the share stanza in the <tt class="filename">smb.conf</tt> file. Turning off “<span class="quote"><span class="emphasis"><em>wide links</em></span></span>” 116 support will degrade server performance because each path must be checked. 117 </p> 118 </td></tr><tr><td align="left"> 119 <p> 120 Privileges Support 121 </p> 122 </td><td align="justify"> 123 <p> 124 Versions of Samba prior to samba-3.0.11 required the use of the UNIX <tt class="constant">root</tt> 125 account from network Windows clients. The new “<span class="quote"><span class="emphasis"><em>enable privileges = Yes</em></span></span>” capability 126 means that functions such as adding machines to the domain, managing printers, etc. can now 127 be delegated to normal user accounts or to groups of users. 128 </p> 129 </td></tr></tbody></table></div></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2464969"></a>Prerequisites</h2></div></div></div><p> 130 This book is not a tutorial on UNIX or Linux administration. UNIX and Linux 131 training is best obtained from books dedicated to the subject. This book 132 assumes that you have at least the basic skill necessary to use these operating 133 systems, and that you can use a basic system editor to edit and configure files. 134 It has been written with the assumption that you have experience with Samba, 135 have read <span class="emphasis"><em>The Official Samba-3 HOWTO and Reference Guide</em></span> and 136 the Samba-HOWTO-Collection, or that you have familiarity with Microsoft Windows. 137 </p><p> 138 If you do not have this experience, you can follow the examples in this book but may 139 find yourself at times intimidated by assumptions made. In this situation, you 140 may need to refer to administrative guides or manuals for your operating system 141 platform to find what is the best method to achieve what the text of this book describes. 142 </p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2465001"></a>Approach</h2></div></div></div><p> 143 The first chapter deals with some rather thorny network analysis issues. Do not be 144 put off by this. The information you glean, even without a detailed understanding 145 of network protocol analysis, can help you understand how Windows networking functions. 146 </p><p> 147 Each following chapter of this book opens with the description of a networking solution 148 sought by a hypothetical site. Bob Jordan is a hypothetical decision maker 149 for an imaginary company, <tt class="constant">Abmas Biz NL</tt>. We will use the 150 non-existent domain name <tt class="constant">abmas.biz</tt>. All <span class="emphasis"><em>facts</em></span> 151 presented regarding this company are fictitious and have been drawn from a variety of real 152 business scenarios over many years. Not one of these reveal the identify of the 153 real-world company from which the scenario originated. 154 </p><p> 155 In any case, Mr. Jordan likes to give all his staff nasty little assignments. 156 Stanley Saroka is one of his proteges; Christine Roberson is the network administrator 157 Bob trusts. Jordan is inclined to treat other departments well because they finance 158 Abmas IT operations. 159 </p><p> 160 Each chapter presents a summary of the network solution we have chosen to 161 demonstrate together with a rationale to help you to understand the 162 thought process that drove that solution. The chapter then documents in precise 163 detail all configuration files and steps that must be taken to implement the 164 example solution. Anyone wishing to gain serious value from this book will 165 do well to take note of the implications of points made, so watch out for the 166 <span class="emphasis"><em>this means that</em></span> notations. 167 </p><p> 168 Each chapter has a set of questions and answers to help you to 169 to understand and digest key attributes of the solutions presented. 170 </p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2465066"></a>Summary of Topics</h2></div></div></div><p> 171 Our first assignment is to understand how Microsoft Windows products 172 function in the network environment. That is where we start. Let's take 173 just a few moments to get a bird's eye view of this book. Remember that 174 this is a book about file and print technology deployment; there are 175 great examples of printing solutions. Here we go. 176 </p><div class="variablelist"><dl><dt><span class="term">Chapter 1 Windows Networking Primer</span></dt><dd><p> 177 Here we cover practical exercises to help us to understand how MS Windows 178 network protocols function. A network protocol analyzer helps you to 179 appreciate the fact that Windows networking is highly dependent on broadcast 180 messaging. Additionally, you can look into network packets that a Windows 181 client sends to a network server to set up a network connection. On completion, 182 you should have a basic understanding of how network browsing functions and 183 have seen some of the information a Windows client sends to 184 a file and print server to create a connection over which file and print 185 operations may take place. 186 </p></dd><dt><span class="term">Chapter 2 No Frills Samba Servers</span></dt><dd><p> 187 Here you design a solution for three different business scenarios, each for a 188 company called Abmas. There are two simple networking problems and one slightly 189 more complex networking challenge. In the first two cases, Abmas has a small 190 simple office, and they want to replace a Windows 9x peer-to-peer network. The 191 third example business uses Windows 2000 Professional. This must be simple, 192 so let's see how far we can get. If successful, Abmas grows quickly and 193 soon needs to replace all servers and workstations. 194 </p><p><span class="emphasis"><em>TechInfo</em></span> This chapter demands: 195 </p><div class="itemizedlist"><ul type="disc"><li><p>Case 1: The simplest <tt class="filename">smb.conf</tt> file that may 196 reasonably be used. Works with Samba-2.x also. This 197 configuration uses Share Mode security. Encrypted 198 passwords are not used, so there is no 199 <tt class="filename">smbpasswd</tt> file. 200 </p></li><li><p>Case 2: Another simple <tt class="filename">smb.conf</tt> file that adds 201 WINS support and printing support. This case deals with 202 a special requirement that demonstrates how to deal with 203 purpose-built software that has a particular requirement 204 for certain share names and printing demands. This 205 configuration uses Share Mode security and also works with 206 Samba-2.x. Encrypted passwords are not used, so there is no 207 <tt class="filename">smbpasswd</tt> file. 208 </p></li><li><p>Case 3: This <tt class="filename">smb.conf</tt> configuration uses User Mode 209 security. The file share configuration demonstrates 210 the ability to provide master access to an administrator 211 while restricting all staff to their own work areas. 212 Encrypted passwords are used, so there is an implicit 213 <tt class="filename">smbpasswd</tt> file. 214 </p></li></ul></div><p> 215 </p></dd><dt><span class="term">Chapter 3 Small Office Networking</span></dt><dd><p> 216 Abmas is a successful company now. They have 50 network users 217 and want a little more varoom from the network. This is a typical 218 small office and they want better systems to help them to grow. This is 219 your chance to really give advanced users a bit more functionality and usefulness. 220 </p><p><span class="emphasis"><em>TechInfo</em></span> This <tt class="filename">smb.conf</tt> file 221 makes use of encrypted passwords, so there is an <tt class="filename">smbpasswd</tt> 222 file. It also demonstrates use of the <i class="parameter"><tt>valid users</tt></i> and 223 <i class="parameter"><tt>valid groups</tt></i> to restrict share access. The Windows 224 clients access the server as Domain members. Mobile users log onto 225 the Domain while in the office, but use a local machine account while on the 226 road. The result is an environment that answers mobile computing user needs. 227 </p></dd><dt><span class="term">Chapter 4 Secure Office Networking</span></dt><dd><p> 228 Abmas is growing rapidly now. Money is a little tight, but with 130 229 network users, security has become a concern. They have many new machines 230 to install and the old equipment will be retired. This time they want the 231 new network to scale and grow for at least two years. Start with a sufficient 232 system and allow room for growth. You are now implementing an Internet 233 connection and have a few reservations about user expectations. 234 </p><p><span class="emphasis"><em>TechInfo</em></span> This <tt class="filename">smb.conf</tt> file 235 makes use of encrypted passwords, and you can use a <tt class="filename">tdbsam</tt> 236 password backend. Domain logons are introduced. Applications are served from the central 237 server. Roaming profiles are mandated. Access to the server is tightened up 238 so that only domain members can access server resources. Mobile computing 239 needs still are catered to. 240 </p></dd><dt><span class="term">Chapter 5 The 500 User Office</span></dt><dd><p> 241 The two-year projections were met. Congratulations, you are a star. 242 Now Abmas needs to replace the network. Into the existing user base, they 243 need to merge a 280-user company they just acquired. It is time to build a serious 244 network. There are now three buildings on one campus and your assignment is 245 to keep everyone working while a new network is rolled out. Oh, isn't it nice 246 to roll out brand new clients and servers! Money is no longer tight, you get 247 to buy and install what you ask for. You will install routers and a firewall. 248 This is exciting! 249 </p><p><span class="emphasis"><em>TechInfo</em></span> This <tt class="filename">smb.conf</tt> file 250 makes use of encrypted passwords, and a <tt class="filename">tdbsam</tt> 251 password backend is used. You are not ready to launch into LDAP yet, so you 252 accept the limitation of having one central Domain Controller with a Domain 253 Member server in two buildings on your campus. A number of clever techniques 254 are used to demonstrate some of the smart options built into Samba. 255 </p></dd><dt><span class="term">Chapter 6 Making Users Happy</span></dt><dd><p> 256 Congratulations again. Abmas is happy with your services and you have been given another raise. 257 Your users are becoming much more capable and are complaining about little 258 things that need to be fixed. Are you up to the task? Mary says it takes her 20 minutes 259 to log onto the network and it is killing her productivity. Email is a bit <span class="emphasis"><em> 260 unreliable</em></span> have you been sleeping on the job? We do not discuss the 261 technology of email but when the use of mail clients breaks because of networking 262 problems, you had better get on top of it. It's time for a change. 263 </p><p><span class="emphasis"><em>TechInfo</em></span> This <tt class="filename">smb.conf</tt> file 264 makes use of encrypted passwords; a distributed <tt class="filename">ldapsam</tt> 265 password backend is used. Roaming profiles are enabled. Desktop profile controls 266 are introduced. Check out the techniques that can improve the user experience 267 of network performance. As a special bonus, this chapter documents how to configure 268 smart downloading of printer drivers for drag-and-drop printing support. And, yes, 269 the secret of configuring CUPS is clearly documented. Go for it; this one will 270 tease you, too. 271 </p></dd><dt><span class="term">Chapter 7 A Distributed 2000-User Network</span></dt><dd><p> 272 Only eight months have passed, and Abmas has acquired another company. You now need to expand 273 the network further. You have to deal with a network that spans several countries. 274 There are three new networks in addition to the original three buildings at the head-office 275 campus. The head office is in New York and you have branch offices in Washington, Los Angeles, and 276 London. Your desktop standard is Windows XP Professional. In many ways, everything has changed 277 and yet it must remain the same. Your team is primed for another roll-out. You know there are 278 further challenges ahead. 279 </p><p><span class="emphasis"><em>TechInfo</em></span> Slave LDAP servers are introduced. Samba is 280 configured to use multiple LDAP backends. This is a brief chapter; it assumes that the 281 technology has been mastered and gets right down to concepts and how to deploy them. 282 </p></dd><dt><span class="term">Chapter 8 Migrating NT4 Domain to Samba-3</span></dt><dd><p> 283 Another six months have 284 passed. Abmas has acquired yet another company. You will find a 285 way to migrate all users off the old network onto the existing network without loss 286 of passwords and will effect the change-over during one weekend. May the force (and caffeine) be with 287 you, may you keep your back to the wind and may the sun shine on your face. 288 </p><p><span class="emphasis"><em>TechInfo</em></span> This chapter demonstrates the use of 289 the <span><b class="command">net rpc migrate</b></span> facility using an LDAP ldapsam backend, and also 290 using a tdbsam passdb backend. Both are much-asked-for examples of NT4 Domain migration. 291 </p></dd><dt><span class="term">Chapter 9 Migrating NetWare 4.11 Server to Samba</span></dt><dd><p> 292 Misty Stanley-Jones has contributed information that summarizes her experience at migration 293 from a NetWare server to Samba-3. 294 </p><p><span class="emphasis"><em>TechInfo</em></span> The documentation provided demonstrates 295 how one site miigrated from NetWare to Samba. Some alternatives tools are mentioned. These 296 could be used to provide another pathway to a successful migration. 297 </p></dd><dt><span class="term">Chapter 10 Adding UNIX/Linux Servers and Clients</span></dt><dd><p> 298 Well done, Bob, your team has achieved much. Now help Abmas integrate the entire network. 299 You want central control and central support and you need to cut costs. How can you reduce administrative 300 overheads and yet get better control of the network? 301 </p><p> 302 This chapter has been contributed by Mark Taylor <tt class="email"><<a href="mailto:mark.taylor@siriusit.co.uk">mark.taylor@siriusit.co.uk</a>></tt> 303 and is based on a live site. For further information regarding this example case, 304 please contact Mark directly. 305 </p><p><span class="emphasis"><em>TechInfo</em></span> It is time to consider how to add Samba servers 306 and UNIX and Linux network clients. Users who convert to Linux want to be able to log on 307 using Windows network accounts. You explore nss_ldap, pam_ldap, winbind, and a few neat 308 techniques for taking control. Are you ready for this? 309 </p></dd><dt><span class="term">Chapter 11 Active Directory, Kerberos and Security</span></dt><dd><p> 310 Abmas has acquired another company that has just migrated to running Windows Server 2003 and 311 Active Directory. One of your staff makes offhand comments that land you in hot water. 312 A network security auditor is hired by the head of the new business and files a damning 313 report, and you must address the <span class="emphasis"><em>defects</em></span> reported. You have hired new 314 network engineers who want to replace Microsoft Active Directory with a pure Kerberos 315 solution. How will you handle this? 316 </p><p><span class="emphasis"><em>TechInfo</em></span> This chapter is your answer. Learn about 317 share access controls, proper use of UNIX/Linux file system access controls, and Windows 318 200x Access Control Lists. Follow these steps to beat the critics. 319 </p></dd><dt><span class="term">Chapter 12 Integrating Additional Services</span></dt><dd><p> 320 The battle is almost over, Samba-3 has won the day. Your team are delighted and now you 321 find yourself at yet another cross-roads. Abmas have acquired a snack food business, you 322 made promises you must keep. IT costs must be reduced, you have new resistance, but you 323 will win again. This time you choose to install the Squid proxy server to validate the 324 fact that Samba is far more than just a file and print server. SPNEGO authentication 325 support means that your Microsoft Windows clients gain transparent proxy access. 326 </p><p><span class="emphasis"><em>TechInfo</em></span> Samba provides the <span><b class="command">ntlm_auth</b></span> 327 module that makes it possible for MS Windows Internet Explorer to connect via the Squid Web 328 and FTP proxy server. You will configure Samba-3 as well as Squid to deliver authenticated 329 access control using the Active Directory Domain user security credentials. 330 </p></dd><dt><span class="term">Chapter 13 Performance, Reliability and Availability</span></dt><dd><p> 331 Bob, are you sure the new Samba server is up to the load? Your network is serving many 332 users who risk becoming unproductive. What can you do to keep ahead of demand? Can you 333 keep the cost under control also? What can go wrong? 334 </p><p><span class="emphasis"><em>TechInfo</em></span> Hot tips that put chili into your 335 network. Avoid name resolution problems, identify potential causes of network collisions, 336 avoid Samba configuration options that will weigh the server down. MS distributed file 337 services to make your network fly and much more. This chapter contains a good deal of 338 “<span class="quote"><span class="emphasis"><em>Did I tell you about this...?</em></span></span>” type of hints to help keep your name on the top 339 performers list. 340 </p></dd></dl></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2463725"></a>Conventions Used</h2></div></div></div><p> 341 The following notation conventions are used throughout this book: 342 </p><div class="itemizedlist"><ul type="disc"><li><p> 343 TOSHARG is used as an abbreviation for the book, “<span class="quote"><span class="emphasis"><em>The Official Samba-3 344 HOWTO and Reference Guide,</em></span></span>” Editors: John H. Terpstra and Jelmer R. Vernooij, 345 Publisher: Prentice Hall, ISBN: 0131453556. 346 </p></li><li><p> 347 Directories and filenames appear in mono-font. For example, 348 <tt class="filename">/etc/pam.conf</tt>. 349 </p></li><li><p> 350 Executable names are bolded. For example, <span><b class="command">smbd</b></span>. 351 </p></li><li><p> 352 Menu items and buttons appear in bold. For example, click <span class="guibutton">Next</span>. 353 </p></li><li><p> 354 Selecting a menu item is indicated as: 355 <span class="guimenu">Start</span>-><span class="guimenuitem">Control Panel</span>-><span class="guimenuitem">Administrative Tools</span>-><span class="guimenuitem">Active Directory Users and Computers</span> 356 </p></li></ul></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="pr03.html">Prev</a>�</td><td width="20%" align="center"><a accesskey="u" href="index.html">Up</a></td><td width="40%" align="right">�<a accesskey="n" href="primer.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Foreword�</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">�Chapter�1.�Networking Primer</td></tr></table></div></body></html> 357