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1 <?xml version="1.0" encoding="iso-8859-1"?>
2 <!DOCTYPE chapter PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
3 <chapter id="small">
4 <title>Small Office Networking</title>
6 <para>
7 <link linkend="simple"/> focused on the basics of simple yet effective
8 network solutions. Network administrators who take pride in their work
9 (that's most of us, right?) take care to deliver what our users want,
10 but not too much more. If we make things too complex, we confound our users
11 and increase costs of network ownership. A professional network manager
12 avoids the temptation to put too much pizazz into the way that the network
13 operates. Some creativity is helpful, but keep it under control &smbmdash;
14 good advice that the following two scenarios illustrate.
15 </para>
17 <para>
18 <indexterm><primary>Netware</primary></indexterm>
19 In one case the network administrator of a mid-sized company spent three
20 months building a new network to replace an old Netware server. What he
21 delivered had all the bells and whistles he could muster. There were a
22 few teething problems during the changeover, nothing serious but a little
23 disruptive all the same. Users were exposed to many changes at once. The
24 network administrator was asked to resign two months after implementing
25 the new system because so many staff complained they had lost time and
26 were not happy with the new network. Everything was automated, and he
27 delivered more features than any advanced user could think of. He was
28 just too smart for his own good.
29 </para>
31 <para>
32 In the case of the other company, a new network manager was appointed
33 to oversee the replacement of a LanTastic network with an MS Windows
34 NT 4.0 network. He had the replacement installed and operational within
35 two weeks. Before installation and changeover, he called a meeting to
36 explain to all users what was going to happen, how it would affect them,
37 and that he would be available 24 hours a day to help them transition.
38 One week after conversion, he held another meeting asking for cooperation
39 in the introduction of a few new features that would help to make life
40 easier. Network users were thrilled with the help he provided. The network
41 he implemented was nowhere near as complex as in the first example, had fewer
42 features, and yet he had happy users. Months later he was still adding
43 new innovations. He always asked the users if a
44 particular feature was what they wanted. He asked his boss for a raise
45 and got it. He often told me, <quote>Always keep a few new tricks up your
46 sleeves for when you need them.</quote> Was he smart? You decide. Let's
47 get on with our next exercise.
48 </para>
50 <sect1>
51 <title>Introduction</title>
53 <para>
54 Abmas Accounting has grown. Mr. Meany likes you and says he knew you
55 were the right person for the job. That's why he asked you to install the
56 new server. The past few months have been hard work. You advised Mr. Meany
57 that it is time for a change. Abmas now has 52 users, having acquired an
58 investment consulting business recently. The new users were added to the
59 network without any problems.
60 </para>
62 <para>
63 Some of the Windows clients are nearly past their use-by date. You found damaged and unusable software on
64 some of the workstations that came with the acquired business and found some machines in need of both
65 hardware and software maintenance.
66 </para>
68 <sect2>
69 <title>Assignment Tasks</title>
71 <para>
72 <indexterm><primary>Windows XP</primary></indexterm>
73 Mr. Meany is retiring in 12 months. Before he goes, he wants you to help ensure
74 that the business is running efficiently. Many of the new staff want notebook
75 computers. They visit customer business premises and need to use local network
76 facilities; these users are technically competent. The company uses a
77 business application that requires Windows XP Professional. In short, a complete
78 client upgrade is about to happen. Mr. Meany told you that he is working
79 on another business acquisition and that by the time he retires there will be
80 80 to 100 users.
81 </para>
83 <para>
84 Mr. Meany is not concerned about security. He wants to make it easier for
85 staff to do their work. He has hired you to help him appoint a full-time
86 network manager before he retires. Above all, he says he is investing in
87 the ability to grow. He is determined to live his lifelong dream and
88 hand the business over to a bright and capable executive who can make
89 things happen. This means your network design must cope well with
90 growth.
91 </para>
93 <para>
94 In a few months, Abmas will require an Internet connection for email and so
95 that staff can easily obtain software updates. Mr. Meany is warming up to
96 the installation of antivirus software but is not yet ready to approve
97 this expense. He told you to spend the money a virus scanner costs
98 on better quality notebook computers for mobile users.
99 </para>
101 <para>
102 One of Mr. Meany's golfing partners convinced him to buy new laser
103 printers, one black only, the other a color laser printer. Staff support
104 the need for a color printer so they can present more attractive proposals
105 and reports.
106 </para>
108 <para>
109 Mr. Meany also asked if it would be possible for one of the staff to manage
110 user accounts from the Windows desktop. That person will be responsible for
111 basic operations.
112 </para>
114 </sect2>
115 </sect1>
117 <sect1>
118 <title>Dissection and Discussion</title>
120 <para>
121 What are the key requirements in this business example? A quick review indicates
122 a need for
123 </para>
125 <itemizedlist>
126 <listitem><para>
127 Scalability, from 52 to over 100 users in 12 months
128 </para></listitem>
130 <listitem><para>
131 Mobile computing capability
132 <indexterm><primary>mobile computing</primary></indexterm>
133 </para></listitem>
135 <listitem><para>
136 Improved reliability and usability
137 </para></listitem>
139 <listitem><para>
140 Easier administration
141 </para></listitem>
142 </itemizedlist>
144 <para>
145 In this instance the installed Linux system is assumed to be a Red Hat Linux Fedora Core2 server
146 (as in <link linkend="AccountingOffice"/>).
148 </para>
151 <sect2>
152 <title>Technical Issues</title>
154 <para>
155 <indexterm><primary>smbpasswd</primary></indexterm>
156 <indexterm><primary>DHCP</primary></indexterm>
157 <indexterm><primary>DNS</primary></indexterm>
158 <indexterm><primary>WINS</primary></indexterm>
159 <indexterm><primary>Domain</primary></indexterm>
160 It is time to implement a domain security environment. You will use the <constant>
161 smbpasswd</constant> (default) backend. You should implement a DHCP server. There is no need to
162 run DNS at this time, but the system will use WINS. The domain name will be <constant>
163 BILLMORE</constant>. This time, the name of the server will be <constant>SLEETH</constant>.
164 </para>
166 <para>
167 All printers will be configured as DHCP clients. The DHCP server will assign
168 the printer a fixed IP address by way of its Ethernet interface (MAC) address.
169 See <link linkend="dhcp01"/>.
170 </para>
172 <note><para>
173 The &smb.conf; file you are creating in this exercise can be used with equal effectiveness
174 with Samba-2.2.x series releases. This is deliberate so that in the next chapter it is
175 possible to start with the installation that you have created here, migrate it
176 to a Samba configuration, and then secure the system further. Configurations following
177 this one utilize features that may not be supported in Samba-2.2.x releases.
178 However, you should note that the examples in each chapter start with the assumption
179 that a fresh new installation is being effected.
180 </para></note>
182 <para>
183 Later on, when the Internet connection is implemented, you will add DNS as well as
184 other enhancements. It is important that you plan accordingly.
185 </para>
187 <para>
188 <indexterm><primary>Ethernet switch</primary></indexterm>
189 You have split the network into two separate areas. Each has its own Ethernet switch.
190 There are 20 users on the accounting network and 32 users on the financial services
191 network. The server has two network interfaces, one serving each network. The
192 network printers will be located in a central area. You plan to install the new
193 printers and keep the old printer in use also.
194 </para>
196 <para>
197 You will provide separate file storage areas for each business entity. The old system
198 will go away, accounting files will be handled under a single directory, and files will
199 be stored under customer name, not under a personal work area. Staff will be made
200 responsible for file location, so the old share point must be maintained.
201 </para>
203 <para>
204 Given that DNS will not be used, you will configure WINS name resolution for UNIX
205 hostname name resolution.
206 </para>
208 <para>
209 <indexterm><primary>Domain</primary><secondary>groups</secondary></indexterm>
210 <indexterm><primary>UNIX</primary><secondary>groups</secondary></indexterm>
211 It is necessary to map Windows Domain Groups to UNIX groups. It is
212 advisable to also map Windows Local Groups to UNIX groups. Additionally, the two
213 key staff groups in the firm are accounting staff and financial services staff.
214 For these, it is necessary to create UNIX groups as well as Windows Domain Groups.
215 </para>
217 <para>
218 In the sample &smb.conf; file, you have configured Samba to call the UNIX
219 <command>groupadd</command> to add group entries. This utility does not permit
220 the addition of group names that contain uppercase characters or spaces. This
221 is considered a bug. The <command>groupadd</command> is part of the
222 <command>shadow-utils</command> open source software package. A later release
223 of this package may have been patched to resolve this bug. If your operating
224 platform has this bug, it means that attempts to add a Windows Domain Group that
225 has either a space or uppercase characters in it will fail. See
226 <emphasis>TOSHARG2</emphasis>, Chapter 11, Section 11.3.1, Example 11.1, for
227 more information.
228 </para>
230 <para>
231 <indexterm><primary>CUPS</primary></indexterm>
232 Vendor-supplied printer drivers will be installed on each client. The CUPS print
233 spooler on the UNIX host will be operated in <constant>raw</constant> mode.
234 </para>
236 </sect2>
238 <sect2>
239 <title>Political Issues</title>
241 <para>
242 Mr. Meany is an old-school manager. He sets the rules and wants to see compliance.
243 He is willing to spend money on things he believes are of value. You need more
244 time to convince him of real priorities.
245 </para>
247 <para>
248 Go ahead, buy better notebooks. Wouldn't it be neat if they happened to be
249 supplied with antivirus software? Above all, demonstrate good purchase value and remember
250 to make your users happy.
251 </para>
253 </sect2>
255 </sect1>
257 <sect1>
258 <title>Implementation</title>
260 <para>
261 <indexterm><primary>migration</primary></indexterm>
262 In this example, the assumption is made that this server is being configured from a clean start.
263 The alternate approach could be to demonstrate the migration of the system that is documented
264 in <link linkend="AcctgNet"/> to meet the new requirements. The decision to treat this case, as with
265 future examples, as a new installation is based on the premise that you can determine
266 the migration steps from the information provided in <link linkend="ntmigration"/>.
267 Additionally, a fresh installation makes the example easier to follow.
268 </para>
270 <para>
271 <indexterm><primary>group membership</primary></indexterm>
272 Each user will be given a home directory on the UNIX system, which will be available as a private
273 share. Two additional shares will be created, one for the accounting department and the other for
274 the financial services department. Network users will be given access to these shares by way
275 of group membership.
276 </para>
278 <para>
279 <indexterm><primary>UNIX</primary><secondary>groups</secondary></indexterm>
280 UNIX group membership is the primary mechanism by which Windows Domain users will be granted
281 rights and privileges within the Windows environment.
282 </para>
284 <para>
285 <indexterm><primary>sticky bit</primary></indexterm>
286 The user <command>alanm</command> will be made the owner of all files. This will be preserved
287 by setting the sticky bit (set UID/GID) on the top-level directories.
288 </para>
290 <para>
291 <figure id="acct2net">
292 <title>Abmas Accounting &smbmdash; 52-User Network Topology</title>
293 <imagefile scale="100">acct2net</imagefile>
294 </figure>
295 </para>
297 <procedure>
298 <title>Server Installation Steps</title>
300 <step><para>
301 Using UNIX/Linux system tools, name the server <constant>sleeth</constant>.
302 </para></step>
304 <step><para>
305 <indexterm><primary>/etc/hosts</primary></indexterm>
306 Place an entry for the machine <constant>sleeth</constant> in the <filename>/etc/hosts</filename>.
307 The printers are network attached, so there should be entries for the
308 network printers also. An example <filename>/etc/hosts</filename> file is shown here:
309 <screen>
310 192.168.1.1 sleeth sleeth1
311 192.168.2.1 sleeth2
312 192.168.1.10 hplj6
313 192.168.1.11 hplj4
314 192.168.2.10 qms
315 </screen>
316 </para></step>
318 <step><para>
319 Install the Samba binary RPM from the Samba-Team FTP site.
320 </para></step>
322 <step><para>
323 Install the ISC DHCP server using the UNIX/Linux system tools available to you.
324 </para></step>
326 <step><para>
327 <indexterm><primary>/etc/rc.d/rc.local</primary></indexterm>
328 <indexterm><primary>IP forwarding</primary></indexterm>
329 <indexterm><primary>router</primary></indexterm>
330 <indexterm><primary>/proc/sys/net/ipv4/ip_forward</primary></indexterm>
331 Because Samba will be operating over two network interfaces and clients on each side
332 may want to be able to reach clients on the other side, it is imperative that IP forwarding
333 is enabled. Use the system tool of your choice to enable IP forwarding. In the
334 absence of such a tool on the Linux system, add to the <filename>/etc/rc.d/rc.local</filename>
335 file an entry as follows:
336 <screen>
337 echo 1 > /proc/sys/net/ipv4/ip_forward
338 </screen>
339 This causes the Linux kernel to forward IP packets so that it acts as a router.
340 </para></step>
342 <step><para>
343 Install the &smb.conf; file as shown in <link linkend="acct2conf"/> and
344 <link linkend="acct3conf"/>. Combine these two examples to form a single
345 <filename>/etc/samba/smb.conf</filename> file.
346 </para></step>
348 <step><para>
349 <indexterm><primary>smbpasswd</primary></indexterm>
350 Add the user <command>root</command> to the Samba password backend:
351 <screen>
352 &rootprompt; smbpasswd -a root
353 New SMB password: XXXXXXX
354 Retype new SMB password: XXXXXXX
355 &rootprompt;
356 </screen>
357 <indexterm><primary>administrator</primary></indexterm>
358 This is the Windows Domain Administrator password. Never delete this account from
359 the password backend after Windows Domain Groups have been initialized. If you delete
360 this account, your system is crippled. You cannot restore this account,
361 and your Samba server can no longer be administered.
362 </para></step>
364 <step><para>
365 <indexterm><primary>username map</primary></indexterm>
366 Create the username map file to permit the <constant>root</constant> account to be called
367 <constant>Administrator</constant> from the Windows network environment. To do this, create
368 the file <filename>/etc/samba/smbusers</filename> with the following contents:
369 <screen>
370 ####
371 # User mapping file
372 ####
373 # File Format
374 # -----------
375 # Unix_ID = Windows_ID
376 #
377 # Examples:
378 # root = Administrator
379 # janes = "Jane Smith"
380 # jimbo = Jim Bones
381 #
382 # Note: If the name contains a space it must be double quoted.
383 # In the example above the name 'jimbo' will be mapped to Windows
384 # user names 'Jim' and 'Bones' because the space was not quoted.
385 #######################################################################
386 root = Administrator
387 ####
388 # End of File
389 ####
390 </screen>
391 </para></step>
393 <step><para>
394 <indexterm><primary>initGrps.sh</primary></indexterm>
395 Create and map Windows Domain Groups to UNIX groups. A sample script is provided in
396 <link linkend="initGrps"/>. Create a file containing this script. We called ours
397 <filename>/etc/samba/initGrps.sh</filename>. Set this file so it can be executed,
398 and then execute the script. Sample output should be as follows:
400 <example id="initGrps">
401 <title>Script to Map Windows NT Groups to UNIX Groups</title>
402 <indexterm><primary>initGrps.sh</primary></indexterm>
403 <screen>
404 #!/bin/bash
405 #
406 # initGrps.sh
407 #
409 # Create UNIX groups
410 groupadd acctsdep
411 groupadd finsrvcs
413 # Map Windows Domain Groups to UNIX groups
414 net groupmap add ntgroup="Domain Admins" unixgroup=root type=d
415 net groupmap add ntgroup="Domain Users" unixgroup=users type=d
416 net groupmap add ntgroup="Domain Guests" unixgroup=nobody type=d
418 # Add Functional Domain Groups
419 net groupmap add ntgroup="Accounts Dept" unixgroup=acctsdep type=d
420 net groupmap add ntgroup="Financial Services" unixgroup=finsrvcs type=d
421 </screen>
422 </example>
424 <screen>
425 &rootprompt; chmod 755 initGrps.sh
426 &rootprompt; cd /etc/samba
427 &rootprompt; ./initGrps.sh
428 Updated mapping entry for Domain Admins
429 Updated mapping entry for Domain Users
430 Updated mapping entry for Domain Guests
431 No rid or sid specified, choosing algorithmic mapping
432 Successfully added group Accounts Dept to the mapping db
433 No rid or sid specified, choosing algorithmic mapping
434 Successfully added group Domain Guests to the mapping db
436 &rootprompt; cd /etc/samba
437 &rootprompt; net groupmap list | sort
438 Account Operators (S-1-5-32-548) -> -1
439 Accounts Dept (S-1-5-21-194350-25496802-3394589-2003) -> acctsdep
440 Administrators (S-1-5-32-544) -> -1
441 Backup Operators (S-1-5-32-551) -> -1
442 Domain Admins (S-1-5-21-194350-25496802-3394589-512) -> root
443 Domain Guests (S-1-5-21-194350-25496802-3394589-514) -> nobody
444 Domain Users (S-1-5-21-194350-25496802-3394589-513) -> users
445 Financial Services (S-1-5-21-194350-25496802-3394589-2005) -> finsrvcs
446 Guests (S-1-5-32-546) -> -1
447 Power Users (S-1-5-32-547) -> -1
448 Print Operators (S-1-5-32-550) -> -1
449 Replicators (S-1-5-32-552) -> -1
450 System Operators (S-1-5-32-549) -> -1
451 Users (S-1-5-32-545) -> -1
452 </screen>
453 </para></step>
455 <step><para>
456 <indexterm><primary>/etc/passwd</primary></indexterm>
457 <indexterm><primary>password</primary><secondary>backend</secondary></indexterm>
458 <indexterm><primary>smbpasswd</primary></indexterm>
459 For each user who needs to be given a Windows Domain account, make an entry in the
460 <filename>/etc/passwd</filename> file as well as in the Samba password backend.
461 Use the system tool of your choice to create the UNIX system accounts, and use the Samba
462 <command>smbpasswd</command> program to create the Domain user accounts.
463 </para>
465 <para>
466 <indexterm><primary>useradd</primary></indexterm>
467 <indexterm><primary>adduser</primary></indexterm>
468 <indexterm><primary>user</primary><secondary>management</secondary></indexterm>
469 There are a number of tools for user management under UNIX, such as
470 <command>useradd</command> and <command>adduser</command>, as well as a plethora of custom
471 tools. With the tool of your choice, create a home directory for each user.
472 </para></step>
474 <step><para>
475 Using the preferred tool for your UNIX system, add each user to the UNIX groups created
476 previously, as necessary. File system access control will be based on UNIX group membership.
477 </para></step>
479 <step><para>
480 Create the directory mount point for the disk subsystem that is mounted to provide
481 data storage for company files. In this case the mount point is indicated in the &smb.conf;
482 file is <filename>/data</filename>. Format the file system as required, mount the formatted
483 file system partition using <command>mount</command>,
484 and make the appropriate changes in <filename>/etc/fstab</filename>.
485 </para></step>
487 <step><para>
488 Create the top-level file storage directories are follows:
489 <screen>
490 &rootprompt; mkdir -p /data/{accounts,finsvcs}
491 &rootprompt; chown -R root:root /data
492 &rootprompt; chown -R alanm:acctsdep /data/accounts
493 &rootprompt; chown -R alanm:finsrvcs /data/finsrvcs
494 &rootprompt; chmod -R ug+rwx,o+rx-w /data
495 </screen>
496 Each department is responsible for creating its own directory structure within its
497 share. The directory root of the <command>accounts</command> share is <filename>/data/accounts</filename>.
498 The directory root of the <command>finsvcs</command> share is <filename>/data/finsvcs</filename>.
499 </para></step>
501 <step><para>
502 Configure the printers with the IP addresses as shown in <link linkend="acct2net"/>.
503 Follow the instructions in the manufacturers' manuals to permit printing to port 9100.
504 This allows the CUPS spooler to print using raw mode protocols.
505 <indexterm><primary>CUPS</primary></indexterm>
506 <indexterm><primary>raw printing</primary></indexterm>
507 </para></step>
509 <step><para>
510 <indexterm><primary>CUPS</primary><secondary>queue</secondary></indexterm>
511 <indexterm><primary>lpadmin</primary></indexterm>
512 Configure the CUPS Print Queues as follows:
513 <screen>
514 &rootprompt; lpadmin -p hplj4 -v socket://192.168.1.11:9100 -E
515 &rootprompt; lpadmin -p hplj6 -v socket://192.168.1.10:9100 -E
516 &rootprompt; lpadmin -p qms -v socket://192.168.2.10:9100 -E
517 </screen>
518 <indexterm><primary>print filter</primary></indexterm>
519 This creates the necessary print queues with no assigned print filter.
520 </para></step>
522 <step><para>
523 <indexterm><primary>mime type</primary></indexterm>
524 <indexterm><primary>/etc/mime.convs</primary></indexterm>
525 <indexterm><primary>application/octet-stream</primary></indexterm>
526 Edit the file <filename>/etc/cups/mime.convs</filename> to uncomment the line:
527 <screen>
528 application/octet-stream application/vnd.cups-raw 0 -
529 </screen>
530 </para></step>
532 <step><para>
533 <indexterm><primary>/etc/mime.types</primary></indexterm>
534 Edit the file <filename>/etc/cups/mime.types</filename> to uncomment the line:
535 <screen>
536 application/octet-stream
537 </screen>
538 </para></step>
540 <step><para>
541 <indexterm><primary>DHCP Server</primary></indexterm>
542 Using your favorite system editor, create an <filename>/etc/dhcpd.conf</filename> with the
543 contents as shown in <link linkend="dhcp01"/>.
544 <example id="dhcp01">
545 <title>Abmas Accounting DHCP Server Configuration File &smbmdash; <filename>/etc/dhcpd.conf</filename></title>
546 <indexterm><primary>/etc/dhcpd.conf</primary></indexterm>
547 <screen>
548 default-lease-time 86400;
549 max-lease-time 172800;
550 default-lease-time 86400;
552 option ntp-servers 192.168.1.1;
553 option domain-name "abmas.biz";
554 option domain-name-servers 192.168.1.1, 192.168.2.1;
555 option netbios-name-servers 192.168.1.1, 192.168.2.1;
556 option netbios-node-type 8;
557 ### NOTE ###
558 # netbios-node-type=8 means set clients to Hybrid Mode
559 # so they will use Unicast communication with the WINS
560 # server and thus reduce the level of UDP broadcast
561 # traffic by up to 90%.
562 ############
564 subnet 192.168.1.0 netmask 255.255.255.0 {
565 range dynamic-bootp 192.168.1.128 192.168.1.254;
566 option subnet-mask 255.255.255.0;
567 option routers 192.168.1.1;
568 allow unknown-clients;
569 host hplj4 {
570 hardware ethernet 08:00:46:7a:35:e4;
571 fixed-address 192.168.1.10;
572 }
573 host hplj6 {
574 hardware ethernet 00:03:47:cb:81:e0;
575 fixed-address 192.168.1.11;
576 }
577 }
578 subnet 192.168.2.0 netmask 255.255.255.0 {
579 range dynamic-bootp 192.168.2.128 192.168.2.254;
580 option subnet-mask 255.255.255.0;
581 option routers 192.168.2.1;
582 allow unknown-clients;
583 host qms {
584 hardware ethernet 01:04:31:db:e1:c0;
585 fixed-address 192.168.1.10;
586 }
587 }
588 subnet 127.0.0.0 netmask 255.0.0.0 {
589 }
590 </screen>
591 </example>
592 </para></step>
595 <step><para>
596 Use the standard system tool to start Samba and CUPS and configure them to start
597 automatically at every system reboot. For example,
598 </para>
600 <para>
601 <indexterm><primary>chkconfig</primary></indexterm>
602 <indexterm><primary>starting dhcpd</primary></indexterm>
603 <indexterm><primary>starting samba</primary></indexterm>
604 <indexterm><primary>starting CUPS</primary></indexterm>
605 <indexterm><primary>chkconfig</primary></indexterm>
606 <screen>
607 &rootprompt; chkconfig dhcp on
608 &rootprompt; chkconfig smb on
609 &rootprompt; chkconfig cups on
610 &rootprompt; /etc/rc.d/init.d/dhcp restart
611 &rootprompt; /etc/rc.d/init.d/smb restart
612 &rootprompt; /etc/rc.d/init.d/cups restart
613 </screen>
614 </para></step>
616 <step><para>
617 <indexterm><primary>name service switch</primary></indexterm>
618 <indexterm><primary>NSS</primary><see>same service switch</see></indexterm>
619 <indexterm><primary>DNS</primary></indexterm>
620 <indexterm><primary>DNS server</primary></indexterm>
621 <indexterm><primary>WINS</primary></indexterm>
622 <indexterm><primary>/etc/nsswitch.conf</primary></indexterm>
623 Configure the name service switch (NSS) to handle WINS-based name resolution.
624 Since this system does not use a DNS server, it is safe to remove this option from
625 the NSS configuration. Edit the <filename>/etc/nsswitch.conf</filename> file so that
626 the <constant>hosts:</constant> entry looks like this:
627 <screen>
628 hosts: files wins
629 </screen>
630 </para></step>
632 </procedure>
634 <example id="acct2conf">
635 <title>Accounting Office Network &smb.conf; File &smbmdash; [globals] Section</title>
636 <smbconfblock>
637 <smbconfcomment>Global parameters</smbconfcomment>
638 <smbconfsection name="[global]"/>
639 <smbconfoption name="workgroup">BILLMORE</smbconfoption>
640 <smbconfoption name="passwd chat">*New*Password* %n\n*Re-enter*new*password* %n\n *Password*changed*</smbconfoption>
641 <smbconfoption name="username map">/etc/samba/smbusers</smbconfoption>
642 <smbconfoption name="syslog">0</smbconfoption>
643 <smbconfoption name="name resolve order">wins bcast hosts</smbconfoption>
644 <smbconfoption name="printcap name">CUPS</smbconfoption>
645 <smbconfoption name="show add printer wizard">No</smbconfoption>
646 <smbconfoption name="add user script">/usr/sbin/useradd -m -G users '%u'</smbconfoption>
647 <smbconfoption name="delete user script">/usr/sbin/userdel -r '%u'</smbconfoption>
648 <smbconfoption name="add group script">/usr/sbin/groupadd '%g'</smbconfoption>
649 <smbconfoption name="delete group script">/usr/sbin/groupdel '%g'</smbconfoption>
650 <smbconfoption name="add user to group script">/usr/sbin/usermod -A '%g' '%u'</smbconfoption>
651 <smbconfoption name="add machine script">/usr/sbin/useradd -s /bin/false -d /var/lib/nobody '%u'</smbconfoption>
652 <smbconfoption name="logon script">scripts\login.bat</smbconfoption>
653 <smbconfoption name="logon path"> </smbconfoption>
654 <smbconfoption name="logon drive">X:</smbconfoption>
655 <smbconfoption name="domain logons">Yes</smbconfoption>
656 <smbconfoption name="preferred master">Yes</smbconfoption>
657 <smbconfoption name="wins support">Yes</smbconfoption>
658 <smbconfoption name="printing">CUPS</smbconfoption>
659 </smbconfblock>
660 </example>
662 <example id="acct3conf">
663 <title>Accounting Office Network &smb.conf; File &smbmdash; Services and Shares Section</title>
664 <smbconfblock>
665 <smbconfsection name="[homes]"/>
666 <smbconfoption name="comment">Home Directories</smbconfoption>
667 <smbconfoption name="valid users">%S</smbconfoption>
668 <smbconfoption name="read only">No</smbconfoption>
669 <smbconfoption name="browseable">No</smbconfoption>
671 <smbconfsection name="[printers]"/>
672 <smbconfoption name="comment">SMB Print Spool</smbconfoption>
673 <smbconfoption name="path">/var/spool/samba</smbconfoption>
674 <smbconfoption name="printable">Yes</smbconfoption>
675 <smbconfoption name="guest ok">Yes</smbconfoption>
676 <smbconfoption name="use client driver">Yes</smbconfoption>
677 <smbconfoption name="browseable">No</smbconfoption>
679 <smbconfsection name="[netlogon]"/>
680 <smbconfoption name="comment">Network Logon Service</smbconfoption>
681 <smbconfoption name="path">/data/%U</smbconfoption>
682 <smbconfoption name="valid users">%S</smbconfoption>
683 <smbconfoption name="read only">No</smbconfoption>
685 <smbconfsection name="[accounts]"/>
686 <smbconfoption name="comment">Accounting Files</smbconfoption>
687 <smbconfoption name="path">/data/accounts</smbconfoption>
688 <smbconfoption name="valid users">%G</smbconfoption>
689 <smbconfoption name="read only">No</smbconfoption>
691 <smbconfsection name="[finsrvcs]"/>
692 <smbconfoption name="comment">Financial Service Files</smbconfoption>
693 <smbconfoption name="path">/data/finsrvcs</smbconfoption>
694 <smbconfoption name="valid users">%G</smbconfoption>
695 <smbconfoption name="read only">No</smbconfoption>
696 </smbconfblock>
697 </example>
699 <sect2>
700 <title>Validation</title>
702 <para>
703 Does everything function as it ought? That is the key question at this point.
704 Here are some simple steps to validate your Samba server configuration.
705 </para>
707 <procedure>
708 <title>Validation Steps</title>
710 <step><para>
711 <indexterm><primary>testparm</primary></indexterm>
712 If your &smb.conf; file has bogus options or parameters, this may cause Samba
713 to refuse to start. The first step should always be to validate the contents
714 of this file by running:
715 <screen>
716 &rootprompt; testparm -s
717 Load smb config files from smb.conf
718 Processing section "[homes]"
719 Processing section "[printers]"
720 Processing section "[netlogon]"
721 Processing section "[accounts]"
722 Processing section "[service]"
723 Loaded services file OK.
724 # Global parameters
725 [global]
726 workgroup = BILLMORE
727 passwd chat = *New*Password* \
728 %n\n *Re-enter*new*password* %n\n *Password*changed*
729 username map = /etc/samba/smbusers
730 syslog = 0
731 name resolve order = wins bcast hosts
732 printcap name = CUPS
733 show add printer wizard = No
734 add user script = /usr/sbin/useradd -m -G users '%u'
735 delete user script = /usr/sbin/userdel -r '%u'
736 add group script = /usr/sbin/groupadd '%g'
737 delete group script = /usr/sbin/groupdel '%g'
738 add user to group script = /usr/sbin/usermod -A '%g' '%u'
739 add machine script = /usr/sbin/useradd
740 -s /bin/false -d /var/lib/nobody '%u'
741 logon script = scripts\logon.bat
742 logon path =
743 logon drive = X:
744 domain logons = Yes
745 preferred master = Yes
746 wins support = Yes
747 ...
748 ### Remainder cut to save space ###
749 </screen>
750 The inclusion of an invalid parameter (say one called dogbert) would generate an
751 error as follows:
752 <screen>
753 Unknown parameter encountered: "dogbert"
754 Ignoring unknown parameter "dogbert"
755 </screen>
756 Clear away all errors before proceeding, and start or restart samba as necessary.
757 </para></step>
759 <step><para>
760 <indexterm><primary>check samba daemons</primary></indexterm>
761 <indexterm><primary>nmbd</primary></indexterm>
762 <indexterm><primary>smbd</primary></indexterm>
763 <indexterm><primary>winbindd</primary></indexterm>
764 Check that the Samba server is running:
765 <screen>
766 &rootprompt; ps ax | grep mbd
767 14244 ? S 0:00 /usr/sbin/nmbd -D
768 14245 ? S 0:00 /usr/sbin/nmbd -D
769 14290 ? S 0:00 /usr/sbin/smbd -D
771 $rootprompt; ps ax | grep winbind
772 14293 ? S 0:00 /usr/sbin/winbindd -D
773 14295 ? S 0:00 /usr/sbin/winbindd -D
774 </screen>
775 The <command>winbindd</command> daemon is running in split mode (normal), so there are also
776 two instances of it. For more information regarding <command>winbindd</command>, see
777 <emphasis>TOSHARG2</emphasis>, Chapter 23, Section 23.3. The single instance of
778 <command>smbd</command> is normal.
779 </para></step>
781 <step><para>
782 <indexterm><primary>anonymous connection</primary></indexterm>
783 Check that an anonymous connection can be made to the Samba server:
784 <screen>
785 &rootprompt; smbclient -L localhost -U%
787 Sharename Type Comment
788 --------- ---- -------
789 netlogon Disk Network Logon Service
790 accounts Disk Accounting Files
791 finsvcs Disk Financial Service Files
792 IPC$ IPC IPC Service (Samba3)
793 ADMIN$ IPC IPC Service (Samba3)
794 hplj4 Printer Hewlett-Packard LaserJet 4
795 hplj6 Printer Hewlett-Packard LaserJet 6
796 qms Printer QMS Magicolor Laser Printer XXXX
798 Server Comment
799 --------- -------
800 SLEETH Samba 3.0.20
802 Workgroup Master
803 --------- -------
804 BILLMORE SLEETH
805 </screen>
806 This demonstrates that an anonymous listing of shares can be obtained. This is the equivalent
807 of browsing the server from a Windows client to obtain a list of shares on the server.
808 The <constant>-U%</constant> argument means to send a <constant>NULL</constant> username and
809 a <constant>NULL</constant> password.
810 </para></step>
812 <step><para>
813 <indexterm><primary>dhcp client validation</primary></indexterm>
814 <indexterm><primary>printer validation</primary></indexterm>
815 <indexterm><primary>/etc/dhcpd.conf</primary></indexterm>
816 Verify that the printers have the IP addresses assigned in the DHCP server configuration file.
817 The easiest way to do this is to ping the printer name. Immediately after the ping response
818 has been received, execute <command>arp -a</command> to find the MAC address of the printer
819 that has responded. Now you can compare the IP address and the MAC address of the printer
820 with the configuration information in the <filename>/etc/dhcpd.conf</filename> file. They
821 should, of course, match. For example,
822 <screen>
823 &rootprompt; ping hplj4
824 PING hplj4 (192.168.1.11) 56(84) bytes of data.
825 64 bytes from hplj4 (192.168.1.11): icmp_seq=1 ttl=64 time=0.113 ms
827 &rootprompt; arp -a
828 hplj4 (192.168.1.11) at 08:00:46:7A:35:E4 [ether] on eth0
829 </screen>
830 The MAC address <constant>08:00:46:7A:35:E4</constant> matches that specified for the
831 IP address from which the printer has responded and the entry for it in the
832 <filename>/etc/dhcpd.conf</filename> file.
833 </para></step>
835 <step><para>
836 <indexterm><primary>authenticated connection</primary></indexterm>
837 Make an authenticated connection to the server using the <command>smbclient</command> tool:
838 <screen>
839 &rootprompt; smbclient //sleeth/accounts -U alanm
840 Password: XXXXXXX
841 smb: \> dir
842 . D 0 Sun Nov 9 01:28:34 2003
843 .. D 0 Sat Aug 16 17:24:26 2003
844 .mc DH 0 Sat Nov 8 21:57:38 2003
845 .qt DH 0 Fri Sep 5 00:48:25 2003
846 SMB D 0 Sun Oct 19 23:04:30 2003
847 Documents D 0 Sat Nov 1 00:31:51 2003
848 xpsp1a_en_x86.exe 131170400 Sun Nov 2 01:25:44 2003
850 65387 blocks of size 65536. 28590 blocks available
851 smb: \> q
852 </screen>
853 </para></step>
855 </procedure>
857 </sect2>
860 <procedure>
861 <title>Windows XP Professional Client Configuration</title>
863 <step><para>
864 Configure clients to the network settings shown in <link linkend="acct2net"/>.
865 All clients use DHCP for TCP/IP protocol stack configuration.
866 <indexterm><primary>WINS</primary></indexterm>
867 <indexterm><primary>DHCP</primary></indexterm>
868 DHCP configures all Windows clients to use the WINS Server address <constant>192.168.1.1</constant>.
869 </para></step>
871 <step><para>
872 Join the Windows Domain called <constant>BILLMORE</constant>. Use the Domain Administrator
873 username <constant>root</constant> and the SMB password you assigned to this account.
874 A detailed step-by-step procedure for joining a Windows 200x/XP Professional client to
875 a Windows Domain is given in <link linkend="appendix"/>, <link linkend="domjoin"/>.
876 Reboot the machine as prompted and then log on using a Domain User account.
877 </para></step>
879 <step><para>
880 Verify on each client that the machine called <constant>SLEETH</constant>
881 is visible in <guimenu>My Network Places</guimenu>, that it is
882 possible to connect to it and see the shares <guimenuitem>accounts</guimenuitem>
883 and <guimenuitem>finsvcs</guimenuitem>,
884 and that it is possible to open that share to reveal its contents.
885 </para></step>
887 <step><para>
888 Instruct all users to log onto the workstation using their assigned username and password.
889 </para></step>
891 <step><para>
892 Install a printer on each using the following steps:
893 </para>
895 <procedure>
896 <step><para>
897 Click <menuchoice>
898 <guimenu>Start</guimenu>
899 <guimenuitem>Settings</guimenuitem>
900 <guimenuitem>Printers</guimenuitem>
901 <guiicon>Add Printer</guiicon>
902 <guibutton>Next</guibutton>
903 </menuchoice>. Do not click <guimenuitem>Network printer</guimenuitem>.
904 Ensure that <guimenuitem>Local printer</guimenuitem> is selected.
905 </para></step>
907 <step><para>
908 Click <guibutton>Next</guibutton>. In the
909 <guimenuitem>Manufacturer:</guimenuitem> panel, select <constant>HP</constant>.
910 In the <guimenuitem>Printers:</guimenuitem> panel, select the printer called
911 <constant>HP LaserJet 4</constant>. Click <guibutton>Next</guibutton>.
912 </para></step>
914 <step><para>
915 In the <guimenuitem>Available ports:</guimenuitem> panel, select
916 <constant>FILE:</constant>. Accept the default printer name by clicking
917 <guibutton>Next</guibutton>. When asked, <quote>Would you like to print a
918 test page?</quote>, click <guimenuitem>No</guimenuitem>. Click
919 <guibutton>Finish</guibutton>.
920 </para></step>
922 <step><para>
923 You may be prompted for the name of a file to print to. If so, close the
924 dialog panel. Right-click <menuchoice>
925 <guiicon>HP LaserJet 4</guiicon>
926 <guimenuitem>Properties</guimenuitem>
927 <guisubmenu>Details (Tab)</guisubmenu>
928 <guimenuitem>Add Port</guimenuitem>
929 </menuchoice>.
930 </para></step>
932 <step><para>
933 In the <guimenuitem>Network</guimenuitem> panel, enter the name of
934 the print queue on the Samba server as follows: <constant>\\SERVER\hplj4</constant>.
935 Click <menuchoice>
936 <guibutton>OK</guibutton>
937 <guibutton>OK</guibutton>
938 </menuchoice> to complete the installation.
939 </para></step>
941 <step><para>
942 Repeat the printer installation steps above for the HP LaserJet 6 printer
943 as well as for the QMS Magicolor XXXX laser printer.
944 </para></step>
945 </procedure>
946 </step>
947 </procedure>
949 <sect2>
950 <title>Notebook Computers: A Special Case</title>
952 <para>
953 As a network administrator, you already know how to create local machine accounts for Windows 200x/XP
954 Professional systems. This is the preferred solution to provide continuity of work for notebook users
955 so that absence from the office network environment does not become a barrier to productivity.
956 </para>
958 <para>
959 By creating a local machine account that has the same username and password as you create for that
960 user in the Windows Domain environment, the user can log onto the machine locally and still
961 transparently access network resources as if logged onto the domain itself. There are some trade-offs
962 that mean that as the network is more tightly secured, it becomes necessary to modify Windows client
963 configuration somewhat.
964 </para>
966 </sect2>
968 <sect2>
969 <title>Key Points Learned</title>
971 <para>
972 In this network design and implementation exercise, you created a Windows NT4-style Domain
973 Controller using Samba-3.0.20. Following these guidelines, you experienced
974 and implemented several important aspects of Windows networking. In the next chapter,
975 you build on the experience. These are the highlights from this chapter:
976 </para>
978 <itemizedlist>
979 <listitem><para>
980 <indexterm><primary>DHCP</primary></indexterm>
981 You implemented a DHCP server, and Microsoft Windows clients were able to obtain all necessary
982 network configuration settings from this server.
983 </para></listitem>
985 <listitem><para>
986 <indexterm><primary>Domain Controller</primary></indexterm>
987 You created a Windows Domain Controller. You were able to use the network logon service
988 and successfully joined Windows 200x/XP Professional clients to the Domain.
989 </para></listitem>
991 <listitem><para>
992 <indexterm><primary>CUPS</primary></indexterm>
993 You created raw print queues in the CUPS printing system. You maintained a simple
994 printing system so that all users can share centrally managed printers. You installed
995 native printer drivers on the Windows clients.
996 </para></listitem>
998 <listitem><para>
999 You experienced the benefits of centrally managed user accounts on the server.
1000 </para></listitem>
1002 <listitem><para>
1003 You offered Mobile notebook users a solution that allows them to continue to work
1004 while away from the office and not connected to the corporate network.
1005 </para></listitem>
1006 </itemizedlist>
1008 </sect2>
1010 </sect1>
1012 <sect1>
1013 <title>Questions and Answers</title>
1015 <para>
1016 Your new Domain Controller is ready to serve you. What does it mean? Here are some questions and answers that
1017 may help.
1018 </para>
1020 <qandaset>
1021 <qandaentry>
1022 <question>
1024 <para>
1025 What is the key benefit of using DHCP to configure Windows client TCP/IP stacks?
1026 </para>
1028 </question>
1029 <answer>
1031 <para>
1032 First and foremost, portability. It means that notebook users can move between
1033 the Abmas office and client offices (so long as they, too, use DHCP) without having to manually
1034 reconfigure their machines. It also means that when they work from their home environments
1035 either using DHCP assigned addressing or when using dial-up networking, settings such as
1036 default routes and DNS server addresses that apply only to the Abmas office environment do
1037 not interfere with remote operations. This is an extremely important feature of DHCP.
1038 </para>
1040 </answer>
1041 </qandaentry>
1043 <qandaentry>
1044 <question>
1046 <para>
1047 Are there any DHCP server configuration parameters in the <filename>/etc/dhcpd.conf</filename>
1048 that should be noted in particular?
1049 </para>
1051 </question>
1052 <answer>
1054 <para>
1055 Yes. The configuration you created automatically provides each client with the IP address
1056 of your WINS server. It also configures the client to preferentially register NetBIOS names
1057 with the WINS server, and then instructs the client to first query the WINS server when a
1058 NetBIOS machine name needs to be resolved to an IP Address. This configuration
1059 results in far lower UDP broadcast traffic than would be the case if WINS was not used.
1060 </para>
1062 </answer>
1063 </qandaentry>
1065 <qandaentry>
1066 <question>
1068 <para>
1069 Is it possible to create a Windows Domain account that is specifically called <constant>Administrator</constant>?
1070 </para>
1072 </question>
1073 <answer>
1075 <para>
1076 You can surely create a Windows Domain account called <constant>Administrator</constant>. It is also
1077 possible to map that account so that it has the effective UNIX UID of 0. This way it isn't
1078 necessary to use the <parameter>username map</parameter> facility to map this account to the UNIX
1079 account called <constant>root</constant>.
1080 </para>
1082 </answer>
1083 </qandaentry>
1085 <qandaentry>
1086 <question>
1088 <para>
1089 Why is it necessary to give the Windows Domain <constant>Administrator</constant> a UNIX UID of 0?
1090 </para>
1092 </question>
1093 <answer>
1095 <para>
1096 The Windows Domain <constant>Administrator</constant> account is the most privileged account that
1097 exists on the Windows platform. This user can change any setting, add, delete, or modify user
1098 accounts, and completely reconfigure the system. The equivalent to this account in the UNIX
1099 environment is the <constant>root</constant> account. If you want to permit the Windows Domain
1100 Administrator to manage accounts as well as permissions, privileges, and security
1101 settings within the Domain and on the Samba server, equivalent rights must be assigned. This is
1102 achieved with the <constant>root</constant> UID equal to 0.
1103 </para>
1105 </answer>
1106 </qandaentry>
1108 <qandaentry>
1109 <question>
1111 <para>
1112 One of my junior staff needs the ability to add machines to the Domain, but I do not want to give him
1113 <constant>root</constant> access. How can we do this?
1114 </para>
1116 </question>
1117 <answer>
1119 <para>
1120 Users who are members of the <constant>Domain Admins</constant> group can add machines to the
1121 Domain. This group is mapped to the UNIX group account called <constant>root</constant>
1122 (or the equivalent <constant>wheel</constant> on some UNIX systems) that has a GID of 0.
1123 This must be the primary GID of the account of the user who is a member of the Windows <constant>
1124 Domain Admins</constant> account.
1125 </para>
1127 </answer>
1128 </qandaentry>
1130 <qandaentry>
1131 <question>
1133 <para>
1134 Why must I map Windows Domain Groups to UNIX groups?
1135 </para>
1137 </question>
1138 <answer>
1140 <para>
1141 Samba does not permit a Domain Group to become visible to Domain network clients unless the account
1142 has a UNIX group account equivalent. The Domain groups that should be given UNIX equivalents are
1143 <guimenu>Domain Guests</guimenu>, <guimenu>Domain Users</guimenu>, and <guimenu>Domain Admins</guimenu>.
1144 </para>
1146 </answer>
1147 </qandaentry>
1149 <qandaentry>
1150 <question>
1152 <para>
1153 I deleted my <constant>root</constant> account and now I cannot add it back! What can I do?
1154 </para>
1156 </question>
1157 <answer>
1159 <para>
1160 This is a nasty problem. Fortunately, there is a solution.
1161 </para>
1163 <procedure>
1164 <step><para>
1165 Back up your existing configuration files in case you need to restore them.
1166 </para></step>
1168 <step><para>
1169 Rename the <filename>group_mapping.tdb</filename> file.
1170 </para></step>
1172 <step><para>
1173 Use the <command>smbpasswd</command> to add the root account.
1174 </para></step>
1176 <step><para>
1177 Restore the <filename>group_mapping.tdb</filename> file.
1178 </para></step>
1179 </procedure>
1181 </answer>
1182 </qandaentry>
1184 <qandaentry>
1185 <question>
1187 <para>
1188 When I run <command>net groupmap list</command>, it reports a group called <guimenu>Administrators</guimenu>
1189 as well as <guimenu>Domain Admins</guimenu>. What is the difference between them?
1190 </para>
1192 </question>
1193 <answer>
1195 <para>
1196 The group called <guimenu>Administrators</guimenu> is representative of the same account that would be
1197 present as the Local Group account on a Domain Member server or workstation. Samba uses only Domain
1198 Groups at this time. A Workstation or Server Local Group has no meaning in a Samba context. This
1199 may change at some later date. These accounts are provided only so that security objects are correctly shown.
1200 </para>
1202 </answer>
1203 </qandaentry>
1205 <qandaentry>
1206 <question>
1208 <para>
1209 What is the effect of changing the name of a Samba server or of changing the Domain name?
1210 </para>
1212 </question>
1213 <answer>
1215 <para>
1216 If you elect to change the name of the Samba server, on restarting <command>smbd</command>,
1217 Windows security identifiers are changed. In the case of a standalone server or a Domain Member server,
1218 the machine SID is changed. This may break Domain membership. In the case of a change of the Domain name
1219 (Workgroup name), the Domain SID is changed. This affects all Domain memberships.
1220 </para>
1222 <para>
1223 If it becomes necessary to change either the server name or the Domain name, be sure to back up the respective
1224 SID before the change is made. You can back up the SID using the <command>net getlocalsid</command> (Samba)
1225 or the <command>smbpasswd</command> (Samba-2.2.x). To change the SID, you use the same tool. Be sure
1226 to check the man page for this command for detailed instructions regarding the steps involved.
1227 </para>
1229 </answer>
1230 </qandaentry>
1232 <qandaentry>
1233 <question>
1235 <para>
1236 How can I manage user accounts from my Windows XP Professional workstation?
1237 </para>
1239 </question>
1240 <answer>
1242 <para>
1243 Samba implements a Windows NT4-style security domain architecture. This type of Domain cannot
1244 be managed using tools present on a Windows XP Professional installation. You may download from the
1245 Microsoft Web site the SRVTOOLS.EXE package. Extract it into the directory from which you wish to use
1246 it. This package extracts the tools: <command>User Manager for Domains</command>, <command>Server Manager</command>, and <command>Event
1247 Viewer</command>. You may use the <guimenu>User Manager for Domains</guimenu> to manage your Samba
1248 Domain user and group accounts. Of course, you do need to be logged on as the <constant>Administrator</constant>
1249 for the Samba Domain. It may help to log on as the <constant>root</constant> account.
1250 </para>
1252 </answer>
1253 </qandaentry>
1255 </qandaset>
1257 </sect1>
1259 </chapter>