1 <html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter 9. Network Browsing</title><link rel="stylesheet" href="samba.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.68.1"><link rel="start" href="index.html" title="The Official Samba-3 HOWTO and Reference Guide"><link rel="up" href="optional.html" title="Part III. Advanced Configuration"><link rel="prev" href="optional.html" title="Part III. Advanced Configuration"><link rel="next" href="passdb.html" title="Chapter 10. Account Information Databases"></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">Chapter 9. Network Browsing</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="optional.html">Prev</a> </td><th width="60%" align="center">Part III. Advanced Configuration</th><td width="20%" align="right"> <a accesskey="n" href="passdb.html">Next</a></td></tr></table><hr></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="NetworkBrowsing"></a>Chapter 9. Network Browsing</h2></div><div><div class="author"><h3 class="author"><span class="firstname">John</span> <span class="othername">H.</span> <span class="surname">Terpstra</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><code class="email"><<a href="mailto:jht@samba.org">jht@samba.org</a>></code></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">Jelmer</span> <span class="othername">R.</span> <span class="surname">Vernooij</span></h3><div class="affiliation"><span class="orgname">The Samba Team<br></span><div class="address"><p><code class="email"><<a href="mailto:jelmer@samba.org">jelmer@samba.org</a>></code></p></div></div></div></div><div><p class="pubdate">July 5, 1998</p></div><div><p class="pubdate">Updated: April 21, 2003</p></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="NetworkBrowsing.html#id2546319">Features and Benefits</a></span></dt><dt><span class="sect1"><a href="NetworkBrowsing.html#id2546502">What Is Browsing?</a></span></dt><dt><span class="sect1"><a href="NetworkBrowsing.html#netdiscuss">Discussion</a></span></dt><dd><dl><dt><span class="sect2"><a href="NetworkBrowsing.html#id2546885">NetBIOS over TCP/IP</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id2547489">TCP/IP without NetBIOS</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#adsdnstech">DNS and Active Directory</a></span></dt></dl></dd><dt><span class="sect1"><a href="NetworkBrowsing.html#id2548048">How Browsing Functions</a></span></dt><dd><dl><dt><span class="sect2"><a href="NetworkBrowsing.html#DMB">Configuring Workgroup Browsing</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id2548972">Domain Browsing Configuration</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#browse-force-master">Forcing Samba to Be the Master</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id2549538">Making Samba the Domain Master</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id2549766">Note about Broadcast Addresses</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id2549788">Multiple Interfaces</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id2549966">Use of the Remote Announce Parameter</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id2550101">Use of the Remote Browse Sync Parameter</a></span></dt></dl></dd><dt><span class="sect1"><a href="NetworkBrowsing.html#id2550191">WINS: The Windows Internetworking Name Server</a></span></dt><dd><dl><dt><span class="sect2"><a href="NetworkBrowsing.html#id2550448">WINS Server Configuration</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id2550754">WINS Replication</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id2550792">Static WINS Entries</a></span></dt></dl></dd><dt><span class="sect1"><a href="NetworkBrowsing.html#id2551023">Helpful Hints</a></span></dt><dd><dl><dt><span class="sect2"><a href="NetworkBrowsing.html#id2551034">Windows Networking Protocols</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id2551184">Name Resolution Order</a></span></dt></dl></dd><dt><span class="sect1"><a href="NetworkBrowsing.html#id2551391">Technical Overview of Browsing</a></span></dt><dd><dl><dt><span class="sect2"><a href="NetworkBrowsing.html#id2551473">Browsing Support in Samba</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id2551662">Problem Resolution</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id2551901">Cross-Subnet Browsing</a></span></dt></dl></dd><dt><span class="sect1"><a href="NetworkBrowsing.html#id2552915">Common Errors</a></span></dt><dd><dl><dt><span class="sect2"><a href="NetworkBrowsing.html#id2552942">Flushing the Samba NetBIOS Name Cache</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id2553015">Server Resources Cannot Be Listed</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id2553059">I Get an "<span class="errorname">Unable to browse the network</span>" Error</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id2553106">Browsing of Shares and Directories is Very Slow</a></span></dt></dl></dd></dl></div><p>
2 <a class="indexterm" name="id2546253"></a>
3 <a class="indexterm" name="id2546260"></a>
4 <a class="indexterm" name="id2546267"></a>
5 This chapter contains detailed information as well as a fast-track guide to
6 implementing browsing across subnets and/or across workgroups (or domains).
7 WINS is the best tool for resolution of NetBIOS names to IP addresses; however, WINS is
8 not involved in browse list handling except by way of name-to-address resolution.
9 </p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
10 <a class="indexterm" name="id2546284"></a>
11 <a class="indexterm" name="id2546291"></a>
12 <a class="indexterm" name="id2546298"></a>
13 <a class="indexterm" name="id2546304"></a>
14 MS Windows 2000 and later versions can be configured to operate with no NetBIOS
15 over TCP/IP. Samba-3 and later versions also support this mode of operation.
16 When the use of NetBIOS over TCP/IP has been disabled, the primary
17 means for resolution of MS Windows machine names is via DNS and Active Directory.
18 The following information assumes that your site is running NetBIOS over TCP/IP.
19 </p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2546319"></a>Features and Benefits</h2></div></div></div><p>
20 Charles Dickens once referred to the past in these words: “<span class="quote"><span class="emphasis"><em>It was the best of times,
21 it was the worst of times.</em></span></span>” The more we look back, the more we long for what was and
22 hope it never returns.
24 <a class="indexterm" name="id2546338"></a>
25 <a class="indexterm" name="id2546345"></a>
26 <a class="indexterm" name="id2546352"></a>
27 For many MS Windows network administrators, that statement sums up their feelings about
28 NetBIOS networking precisely. For those who mastered NetBIOS networking, its fickle
29 nature was just par for the course. For those who never quite managed to tame its
30 lusty features, NetBIOS is like Paterson's Curse.
32 For those not familiar with botanical problems in Australia, Paterson's Curse,
33 <span class="emphasis"><em>Echium plantagineum</em></span>, was introduced to Australia from Europe during the mid-19th
34 century. Since then it has spread rapidly. The high seed production, with densities of
35 thousands of seeds per square meter, a seed longevity of more than 7 years, and an
36 ability to germinate at any time of year, given the right conditions, are some of the
37 features that make it such a persistent weed.
39 <a class="indexterm" name="id2546381"></a>
40 <a class="indexterm" name="id2546391"></a>
41 <a class="indexterm" name="id2546397"></a>
42 <a class="indexterm" name="id2546404"></a>
43 <a class="indexterm" name="id2546411"></a>
44 In this chapter we explore vital aspects of Server Message Block (SMB) networking with
45 a particular focus on SMB as implemented through running NetBIOS (Network Basic
46 Input/Output System) over TCP/IP. Since Samba does not implement SMB or NetBIOS over
47 any other protocols, we need to know how to configure our network environment and simply
48 remember to use nothing but TCP/IP on all our MS Windows network clients.
50 <a class="indexterm" name="id2546428"></a>
51 <a class="indexterm" name="id2546435"></a>
52 Samba provides the ability to implement a WINS (Windows Internetworking Name Server)
53 and implements extensions to Microsoft's implementation of WINS. These extensions
54 help Samba to effect stable WINS operations beyond the normal scope of MS WINS.
56 <a class="indexterm" name="id2546449"></a>
57 <a class="indexterm" name="id2546456"></a>
58 <a class="indexterm" name="id2546463"></a>
59 WINS is exclusively a service that applies only to those systems
60 that run NetBIOS over TCP/IP. MS Windows 200x/XP have the capacity to operate with
61 support for NetBIOS disabled, in which case WINS is of no relevance. Samba supports this also.
63 <a class="indexterm" name="id2546478"></a>
64 <a class="indexterm" name="id2546484"></a>
65 <a class="indexterm" name="id2546491"></a>
66 For those networks on which NetBIOS has been disabled (i.e., WINS is not required),
67 the use of DNS is necessary for hostname resolution.
68 </p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2546502"></a>What Is Browsing?</h2></div></div></div><p>
69 <a class="indexterm" name="id2546510"></a>
70 <a class="indexterm" name="id2546517"></a>
71 <a class="indexterm" name="id2546524"></a>
72 <a class="indexterm" name="id2546531"></a>
73 To most people, browsing means they can see the MS Windows and Samba servers
74 in the Network Neighborhood, and when the computer icon for a particular server is
75 clicked, it opens up and shows the shares and printers available on the target server.
77 What seems so simple is in fact a complex interaction of different technologies.
78 The technologies (or methods) employed in making all of this work include:
79 </p><div class="itemizedlist"><ul type="disc"><li><p>MS Windows machines register their presence to the network.</p></li><li><p>Machines announce themselves to other machines on the network.</p></li><li><p>One or more machines on the network collate the local announcements.</p></li><li><p>The client machine finds the machine that has the collated list of machines.</p></li><li><p>The client machine is able to resolve the machine names to IP addresses.</p></li><li><p>The client machine is able to connect to a target machine.</p></li></ul></div><p>
80 <a class="indexterm" name="id2546588"></a>
81 <a class="indexterm" name="id2546595"></a>
82 <a class="indexterm" name="id2546602"></a>
83 The Samba application that controls browse list management and name resolution is
84 called <code class="filename">nmbd</code>. The configuration parameters involved in nmbd's operation are:
87 </p><div class="itemizedlist"><ul type="disc"><li><a class="indexterm" name="id2546625"></a>os level</li><li><a class="indexterm" name="id2546634"></a>lm announce</li><li><a class="indexterm" name="id2546643"></a>lm interval</li><li><a class="indexterm" name="id2546652"></a>preferred master(*)</li><li><a class="indexterm" name="id2546662"></a>local master(*)</li><li><a class="indexterm" name="id2546671"></a>domain master(*)</li><li><a class="indexterm" name="id2546681"></a>browse list</li><li><a class="indexterm" name="id2546690"></a>enhanced browsing</li></ul></div><p>
88 Name Resolution Method:
89 </p><div class="itemizedlist"><ul type="disc"><li><a class="indexterm" name="id2546706"></a>name resolve order(*)</li></ul></div><p>
91 </p><div class="itemizedlist"><ul type="disc"><li><a class="indexterm" name="id2546723"></a>dns proxy</li><li><a class="indexterm" name="id2546732"></a>wins proxy</li><li><a class="indexterm" name="id2546741"></a>wins server(*)</li><li><a class="indexterm" name="id2546750"></a>wins support(*)</li><li><a class="indexterm" name="id2546760"></a>wins hook</li></ul></div><p>
92 Those marked with an (*) are the only options that commonly may need to be modified. Even if none of these
93 parameters is set, <code class="filename">nmbd</code> will still do its job.
95 <a class="indexterm" name="id2546783"></a>
96 <a class="indexterm" name="id2546790"></a>
97 <a class="indexterm" name="id2546797"></a>
98 <a class="indexterm" name="id2546804"></a>
99 <a class="indexterm" name="id2546810"></a>
100 For Samba, the WINS Server and WINS Support are mutually exclusive options. When <span><strong class="command">nmbd</strong></span> is
101 started it will fail to execute if both options are set in the <code class="filename">smb.conf</code> file. The <span><strong class="command">nmbd</strong></span>
102 understands that when it spawns an instance of itself to run as a WINS server that it has to use its own WINS
104 </p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="netdiscuss"></a>Discussion</h2></div></div></div><p>
105 <a class="indexterm" name="id2546853"></a>
106 <a class="indexterm" name="id2546860"></a>
107 <a class="indexterm" name="id2546866"></a>
108 <a class="indexterm" name="id2546873"></a>
109 All MS Windows networking uses SMB-based messaging. SMB messaging may be implemented with or without NetBIOS.
110 MS Windows 200x supports NetBIOS over TCP/IP for backwards compatibility. Microsoft appears intent on phasing
112 </p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2546885"></a>NetBIOS over TCP/IP</h3></div></div></div><p>
113 <a class="indexterm" name="id2546893"></a>
114 <a class="indexterm" name="id2546900"></a>
115 <a class="indexterm" name="id2546907"></a>
116 <a class="indexterm" name="id2546914"></a>
117 Samba implements NetBIOS, as does MS Windows NT/200x/XP, by encapsulating it over TCP/IP.
118 NetBIOS-based networking uses broadcast messaging to effect browse list management. When running NetBIOS over
119 TCP/IP, this uses UDP-based messaging. UDP messages can be broadcast or unicast.
121 <a class="indexterm" name="id2546928"></a>
122 Normally, only unicast UDP messaging can be forwarded by routers. The
123 <a class="indexterm" name="id2546936"></a>remote announce parameter to smb.conf helps to project browse announcements
124 to remote network segments via unicast UDP. Similarly, the
125 <a class="indexterm" name="id2546946"></a>remote browse sync parameter of <code class="filename">smb.conf</code>
126 implements browse list collation using unicast UDP.
128 The methods used by MS Windows to perform name lookup requests (name resolution) is determined by a
129 configuration parameter called the NetBIOS node-type. There are four basic NetBIOS node types:
130 </p><a class="indexterm" name="id2546968"></a><a class="indexterm" name="id2546974"></a><a class="indexterm" name="id2546981"></a><a class="indexterm" name="id2546988"></a><a class="indexterm" name="id2546995"></a><a class="indexterm" name="id2547002"></a><a class="indexterm" name="id2547008"></a><a class="indexterm" name="id2547015"></a><div class="itemizedlist"><ul type="disc"><li><p><span class="emphasis"><em>b-node (type 0x01):</em></span> The Windows client will use only
131 NetBIOS broadcast requests using UDP broadcast.</p></li><li><p><span class="emphasis"><em>p-node (type 0x02):</em></span> The Windows client will use point-to-point
132 (NetBIOS unicast) requests using UDP unicast directed to a WINS server.</p></li><li><p><span class="emphasis"><em>m-node (type 0x04):</em></span> The Windows client will first use
133 NetBIOS broadcast requests using UDP broadcast, then it will use (NetBIOS unicast)
134 requests using UDP unicast directed to a WINS server.</p></li><li><p><span class="emphasis"><em>h-node (type 0x08):</em></span> The Windows client will use
135 (NetBIOS unicast) requests using UDP unicast directed to a WINS server, then it will use
136 NetBIOS broadcast requests using UDP broadcast.</p></li></ul></div><p>
137 <a class="indexterm" name="id2547064"></a>
138 <a class="indexterm" name="id2547071"></a>
139 <a class="indexterm" name="id2547078"></a>
140 <a class="indexterm" name="id2547085"></a>
141 <a class="indexterm" name="id2547092"></a>
142 <a class="indexterm" name="id2547099"></a>
143 The default Windows network client (or server) network configuration enables NetBIOS over TCP/IP
144 and b-node configuration. The use of WINS makes most sense with h-node (hybrid mode) operation so that
145 in the event of a WINS breakdown or non-availability, the client can use broadcast-based name resolution.
147 <a class="indexterm" name="id2547114"></a>
148 <a class="indexterm" name="id2547123"></a>
149 <a class="indexterm" name="id2547130"></a>
150 <a class="indexterm" name="id2547137"></a>
151 <a class="indexterm" name="id2547144"></a>
152 <a class="indexterm" name="id2547150"></a>
153 <a class="indexterm" name="id2547157"></a>
154 In those networks where Samba is the only SMB server technology, wherever possible <code class="filename">nmbd</code>
155 should be configured on one machine as the WINS server. This makes it easy to manage the browsing environment.
156 If each network segment is configured with its own Samba WINS server, then the only way to get cross-segment
157 browsing to work is by using the <a class="indexterm" name="id2547176"></a>remote announce and the <a class="indexterm" name="id2547184"></a>remote browse sync parameters to your <code class="filename">smb.conf</code> file.
159 <a class="indexterm" name="id2547200"></a>
160 If only one WINS server is used for an entire multisegment network, then
161 the use of the <a class="indexterm" name="id2547209"></a>remote announce and the
162 <a class="indexterm" name="id2547216"></a>remote browse sync parameters should not be necessary.
164 <a class="indexterm" name="id2547228"></a>
165 As of Samba-3, WINS replication is being worked on. The bulk of the code has been committed, but it still
166 needs maturation. This is not a supported feature of the Samba-3.0.20 release. Hopefully, this will become a
167 supported feature of one of the Samba-3 release series. The delay is caused by the fact that this feature has
168 not been of sufficient significance to inspire someone to pay a developer to complete it.
170 <a class="indexterm" name="id2547247"></a>
171 <a class="indexterm" name="id2547254"></a>
172 <a class="indexterm" name="id2547261"></a>
173 <a class="indexterm" name="id2547268"></a>
174 <a class="indexterm" name="id2547274"></a>
175 <a class="indexterm" name="id2547281"></a>
176 <a class="indexterm" name="id2547288"></a>
177 <a class="indexterm" name="id2547295"></a>
178 Right now Samba WINS does not support MS-WINS replication. This means that when setting up Samba as a WINS
179 server, there must only be one <code class="filename">nmbd</code> configured as a WINS server on the network. Some
180 sites have used multiple Samba WINS servers for redundancy (one server per subnet) and then used
181 <a class="indexterm" name="id2547312"></a>remote browse sync and <a class="indexterm" name="id2547320"></a>remote announce to effect browse list
182 collation across all segments. Note that this means clients will only resolve local names and must be
183 configured to use DNS to resolve names on other subnets in order to resolve the IP addresses of the servers
184 they can see on other subnets. This setup is not recommended but is mentioned as a practical consideration
185 (i.e., an “<span class="quote">if all else fails</span>” scenario). NetBIOS over TCP/IP is an ugly and difficult to manage
186 protocol. Its replacement, NetBIOSless SMB over TCP/IP is not without its own manageability concerns. NetBIOS
187 based networking is a life of compromise and trade-offs. WINS stores information that cannot be stored in
188 DNS; consequently, DNS is a poor substitute for WINS given that when NetBIOS over TCP/IP is used, Windows
189 clients are designed to use WINS.
191 <a class="indexterm" name="id2547347"></a>
192 <a class="indexterm" name="id2547354"></a>
193 <a class="indexterm" name="id2547361"></a>
194 Lastly, take note that browse lists are a collection of unreliable broadcast
195 messages that are repeated at intervals of not more than 15 minutes. This means
196 that it will take time to establish a browse list, and it can take up to 45
197 minutes to stabilize, particularly across network segments.
199 <a class="indexterm" name="id2547376"></a>
200 When an MS Windows 200x/XP system attempts to resolve a host name to an IP address, it follows a defined path:
201 </p><div class="orderedlist"><ol type="1"><li><p>
202 Checks the <code class="filename">hosts</code> file. It is located in <code class="filename">%SystemRoot%\System32\Drivers\etc</code>.
206 Checks the NetBIOS name cache.
208 Queries the WINS server.
210 Does a broadcast name lookup over UDP.
212 Looks up entries in LMHOSTS, located in <code class="filename">%SystemRoot%\System32\Drivers\etc</code>.
213 </p></li></ol></div><p>
214 <a class="indexterm" name="id2547444"></a>
215 <a class="indexterm" name="id2547451"></a>
216 <a class="indexterm" name="id2547458"></a>
217 <a class="indexterm" name="id2547465"></a>
218 Given the nature of how the NetBIOS over TCP/IP protocol is implemented, only WINS is capable of resolving
219 with any reliability name lookups for service-oriented names such as TEMPTATION<1C> a NetBIOS
220 name query that seeks to find network logon servers. DNS has no concept of service-oriented names such as
221 this. In fact, the Microsoft ADS implementation specifically manages a whole range of extended
222 service-oriented DNS entries. This type of facility is not implemented and is not supported for the NetBIOS
223 over TCP/IP protocol namespace.
224 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2547489"></a>TCP/IP without NetBIOS</h3></div></div></div><p>
225 <a class="indexterm" name="id2547496"></a>
226 <a class="indexterm" name="id2547503"></a>
227 <a class="indexterm" name="id2547510"></a>
228 All TCP/IP-enabled systems use various forms of hostname resolution. The primary
229 methods for TCP/IP hostname resolution involve either a static file (<code class="filename">/etc/hosts</code>)
230 or the Domain Name System (DNS). DNS is the technology that makes
231 the Internet usable. DNS-based hostname resolution is supported by nearly all
232 TCP/IP-enabled systems. Only a few embedded TCP/IP systems do not support DNS.
234 <a class="indexterm" name="id2547532"></a>
235 <a class="indexterm" name="id2547539"></a>
236 <a class="indexterm" name="id2547546"></a>
237 <a class="indexterm" name="id2547552"></a>
238 Windows 200x/XP can register its hostname with a Dynamic DNS server (DDNS). It is possible to force register with a
239 dynamic DNS server in Windows 200x/XP using <span><strong class="command">ipconfig /registerdns</strong></span>.
241 <a class="indexterm" name="id2547574"></a>
242 <a class="indexterm" name="id2547580"></a>
243 <a class="indexterm" name="id2547587"></a>
244 With Active Directory, a correctly functioning DNS server is absolutely essential. In the absence of a working
245 DNS server that has been correctly configured, MS Windows clients and servers will be unable to locate each
246 other, so network services consequently will be severely impaired.
248 <a class="indexterm" name="id2547602"></a>
249 <a class="indexterm" name="id2547609"></a>
250 <a class="indexterm" name="id2547616"></a>
251 <a class="indexterm" name="id2547622"></a>
252 <a class="indexterm" name="id2547629"></a>
253 <a class="indexterm" name="id2547636"></a>
254 Use of raw SMB over TCP/IP (No NetBIOS layer) can be done only with Active Directory domains. Samba is not an
255 Active Directory domain controller: ergo, it is not possible to run Samba as a domain controller and at the same
256 time <span class="emphasis"><em>not</em></span> use NetBIOS. Where Samba is used as an Active Directory domain member server
257 (DMS) it is possible to configure Samba to not use NetBIOS over TCP/IP. A Samba DMS can integrate fully into
258 an Active Directory domain, however, if NetBIOS over TCP/IP is disabled, it is necessary to manually create
259 appropriate DNS entries for the Samba DMS because they will not be automatically generated either by Samba, or
260 by the ADS environment.
261 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="adsdnstech"></a>DNS and Active Directory</h3></div></div></div><p>
262 <a class="indexterm" name="id2547671"></a>
263 <a class="indexterm" name="id2547680"></a>
264 <a class="indexterm" name="id2547687"></a>
265 <a class="indexterm" name="id2547693"></a>
266 <a class="indexterm" name="id2547700"></a>
267 Occasionally we hear from UNIX network administrators who want to use a UNIX-based DDNS server in place
268 of the Microsoft DNS server. While this might be desirable to some, the MS Windows 200x DNS server is
269 autoconfigured to work with Active Directory. It is possible to use BIND version 8 or 9, but it will almost
270 certainly be necessary to create service records (SRV records) so MS Active Directory clients can resolve
271 hostnames to locate essential network services. The following are some of the default service records that
272 Active Directory requires:
274 <a class="indexterm" name="id2547722"></a>
275 <a class="indexterm" name="id2547728"></a>
276 <a class="indexterm" name="id2547735"></a>
277 The use of DDNS is highly recommended with Active Directory, in which case the use of BIND9 is preferred for
278 its ability to adequately support the SRV (service) records that are needed for Active Directory. Of course,
279 when running ADS, it makes sense to use Microsoft's own DDNS server because of the natural affinity between ADS
281 </p><div class="variablelist"><dl><dt><span class="term">_ldap._tcp.pdc._msdcs.<span class="emphasis"><em>Domain</em></span></span></dt><dd><p>
282 This provides the address of the Windows NT PDC for the domain.
283 </p></dd><dt><span class="term">_ldap._tcp.pdc._msdcs.<span class="emphasis"><em>DomainTree</em></span></span></dt><dd><p>
284 Resolves the addresses of global catalog servers in the domain.
285 </p></dd><dt><span class="term">_ldap._tcp.<span class="emphasis"><em>site</em></span>.sites.writable._msdcs.<span class="emphasis"><em>Domain</em></span></span></dt><dd><p>
286 Provides list of domain controllers based on sites.
287 </p></dd><dt><span class="term">_ldap._tcp.writable._msdcs.<span class="emphasis"><em>Domain</em></span></span></dt><dd><p>
288 Enumerates list of domain controllers that have the writable copies of the Active Directory data store.
289 </p></dd><dt><span class="term">_ldap._tcp.<span class="emphasis"><em>GUID</em></span>.domains._msdcs.<span class="emphasis"><em>DomainTree</em></span></span></dt><dd><p>
290 Entry used by MS Windows clients to locate machines using the global unique identifier.
291 </p></dd><dt><span class="term">_ldap._tcp.<span class="emphasis"><em>Site</em></span>.gc._msdcs.<span class="emphasis"><em>DomainTree</em></span></span></dt><dd><p>
292 Used by Microsoft Windows clients to locate the site configuration-dependent global catalog server.
293 </p></dd></dl></div><p>
294 Specific entries used by Microsoft clients to locate essential services for an example domain
295 called <code class="constant">quenya.org</code> include:
296 </p><div class="itemizedlist"><ul type="disc"><li><p>
297 _kerberos._udp.quenya.org Used to contact the KDC server via UDP.
298 This entry must list port 88 for each KDC.
300 _kpasswd._udp.quenya.org Used to locate the <code class="constant">kpasswd</code> server
301 when a user password change must be processed. This record must list port 464 on the
304 _kerberos._tcp.quenya.org Used to locate the KDC server via TCP.
305 This entry must list port 88 for each KDC.
307 _ldap._tcp.quenya.org Used to locate the LDAP service on the PDC.
308 This record must list port 389 for the PDC.
310 _kpasswd._tcp.quenya.org Used to locate the <code class="constant">kpasswd</code> server
311 to permit user password changes to be processed. This must list port 464.
313 _gc._tcp.quenya.org Used to locate the global catalog server for the
314 top of the domain. This must list port 3268.
315 </p></li></ul></div><p>
316 The following records are also used by the Windows domain member client to locate vital
317 services on the Windows ADS domain controllers.
318 </p><div class="itemizedlist"><ul type="disc"><li><p>
319 _ldap._tcp.pdc._msdcs.quenya.org
321 _ldap.gc._msdcs.quenya.org
323 _ldap.default-first-site-name._sites.gc._msdcs.quenya.org
325 _ldap.{SecID}.domains._msdcs.quenya.org
327 _ldap._tcp.dc._msdcs.quenya.org
329 _kerberos._tcp.dc._msdcs.quenya.org
331 _ldap.default-first-site-name._sites.dc._msdcs.quenya.org
333 _kerberos.default-first-site-name._sites.dc._msdcs.queyna.org
335 SecID._msdcs.quenya.org
336 </p></li></ul></div><p>
337 Presence of the correct DNS entries can be validated by executing:
338 </p><pre class="screen">
339 <code class="prompt">root# </code> dig @frodo -t any _ldap._tcp.dc._msdcs.quenya.org
341 ; <lt;>> DiG 9.2.2 <lt;>> @frodo -t any _ldap._tcp.dc._msdcs.quenya.org
342 ;; global options: printcmd
344 ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3072
345 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 2
349 ;_ldap._tcp.dc._msdcs.quenya.org. IN ANY
353 _ldap._tcp.dc._msdcs.quenya.org. 600 IN SRV 0 100 389 frodo.quenya.org.
354 _ldap._tcp.dc._msdcs.quenya.org. 600 IN SRV 0 100 389 noldor.quenya.org.
357 ;; ADDITIONAL SECTION:
358 frodo.quenya.org. 3600 IN A 10.1.1.16
359 noldor.quenya.org. 1200 IN A 10.1.1.17
362 ;; Query time: 0 msec
363 ;; SERVER: frodo#53(10.1.1.16)
364 ;; WHEN: Wed Oct 7 14:39:31 2004
365 ;; MSG SIZE rcvd: 171
367 </p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2548048"></a>How Browsing Functions</h2></div></div></div><p>
368 <a class="indexterm" name="id2548056"></a>
369 <a class="indexterm" name="id2548063"></a>
370 <a class="indexterm" name="id2548070"></a>
371 <a class="indexterm" name="id2548076"></a>
372 <a class="indexterm" name="id2548083"></a>
373 MS Windows machines register their NetBIOS names (i.e., the machine name for each service type in operation)
374 on startup. The exact method by which this name registration takes place is determined by whether or not the
375 MS Windows client/server has been given a WINS server address, whether or not LMHOSTS lookup is enabled,
376 whether or not DNS for NetBIOS name resolution is enabled, and so on.
378 <a class="indexterm" name="id2548100"></a>
379 <a class="indexterm" name="id2548107"></a>
380 <a class="indexterm" name="id2548114"></a>
381 In the case where there is no WINS server, all name registrations as well as name lookups are done by UDP
382 broadcast. This isolates name resolution to the local subnet, unless LMHOSTS is used to list all names and IP
383 addresses. In such situations, Samba provides a means by which the Samba server name may be forcibly injected
384 into the browse list of a remote MS Windows network (using the <a class="indexterm" name="id2548127"></a>remote announce
387 <a class="indexterm" name="id2548138"></a>
388 <a class="indexterm" name="id2548144"></a>
389 <a class="indexterm" name="id2548151"></a>
390 Where a WINS server is used, the MS Windows client will use UDP unicast to register with the WINS server. Such
391 packets can be routed, and thus WINS allows name resolution to function across routed networks.
393 <a class="indexterm" name="id2548165"></a>
394 <a class="indexterm" name="id2548172"></a>
395 <a class="indexterm" name="id2548181"></a>
396 <a class="indexterm" name="id2548188"></a>
397 <a class="indexterm" name="id2548195"></a>
398 <a class="indexterm" name="id2548201"></a>
399 <a class="indexterm" name="id2548208"></a>
400 <a class="indexterm" name="id2548215"></a>
401 During the startup process, an election takes place to create a local master browser (LMB) if one does not
402 already exist. On each NetBIOS network one machine will be elected to function as the domain master browser
403 (DMB). This domain browsing has nothing to do with MS security Domain Control. Instead, the DMB serves the
404 role of contacting each LMB (found by asking WINS or from LMHOSTS) and exchanging browse list contents. This
405 way every master browser will eventually obtain a complete list of all machines that are on the network. Every
406 11 to 15 minutes an election is held to determine which machine will be the master browser. By the nature of
407 the election criteria used, the machine with the highest uptime, or the most senior protocol version or other
408 criteria, will win the election as DMB.
410 <a class="indexterm" name="id2548238"></a>
411 <a class="indexterm" name="id2548245"></a>
412 <a class="indexterm" name="id2548252"></a>
413 <a class="indexterm" name="id2548259"></a>
414 <a class="indexterm" name="id2548266"></a>
415 <a class="indexterm" name="id2548273"></a>
416 <a class="indexterm" name="id2548279"></a>
417 <a class="indexterm" name="id2548286"></a>
418 Where a WINS server is used, the DMB registers its IP address with the WINS server using the name of the
419 domain and the NetBIOS name type 1B (e.g., DOMAIN<1B>). All LMBs register their IP addresses with the WINS
420 server, also with the name of the domain and the NetBIOS name type of 1D. The 1B name is unique to one
421 server within the domain security context, and only one 1D name is registered for each network segment.
422 Machines that have registered the 1D name will be authoritive browse list maintainers for the network segment
423 they are on. The DMB is responsible for synchronizing the browse lists it obtains from the LMBs.
425 <a class="indexterm" name="id2548322"></a>
426 Clients wishing to browse the network make use of this list but also depend on the availability of correct
427 name resolution to the respective IP address or addresses.
429 <a class="indexterm" name="id2548335"></a>
430 Any configuration that breaks name resolution and/or browsing intrinsics will annoy users because they will
431 have to put up with protracted inability to use the network services.
433 <a class="indexterm" name="id2548349"></a>
434 <a class="indexterm" name="id2548356"></a>
435 <a class="indexterm" name="id2548362"></a>
436 <a class="indexterm" name="id2548369"></a>
437 <a class="indexterm" name="id2548376"></a>
438 <a class="indexterm" name="id2548383"></a>
439 Samba supports a feature that allows forced synchronization of browse lists across routed networks using the
440 <a class="indexterm" name="id2548392"></a>remote browse sync parameter in the <code class="filename">smb.conf</code> file. This causes Samba to contact the
441 LMB on a remote network and to request browse list synchronization. This effectively bridges two networks that
442 are separated by routers. The two remote networks may use either broadcast-based name resolution or WINS-based
443 name resolution, but it should be noted that the <a class="indexterm" name="id2548410"></a>remote browse sync parameter provides
444 browse list synchronization and that is distinct from name-to-address resolution. In other words,
445 for cross-subnet browsing to function correctly, it is essential that a name-to-address resolution mechanism
446 be provided. This mechanism could be via DNS, <code class="filename">/etc/hosts</code>, and so on.
447 </p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="DMB"></a>Configuring Workgroup Browsing</h3></div></div></div><p>
448 <a class="indexterm" name="id2548443"></a>
449 <a class="indexterm" name="id2548450"></a>
450 <a class="indexterm" name="id2548457"></a>
451 <a class="indexterm" name="id2548463"></a>
452 <a class="indexterm" name="id2548470"></a>
453 <a class="indexterm" name="id2548477"></a>
454 To configure cross-subnet browsing on a network containing machines in a workgroup, not an NT domain, you need
455 to set up one Samba server to be the DMB (note that this is not the same as a Primary Domain Controller,
456 although in an NT domain the same machine plays both roles). The role of a DMB is to collate the browse lists
457 from LMB on all the subnets that have a machine participating in the workgroup. Without one machine configured
458 as a DMB, each subnet would be an isolated workgroup unable to see any machines on another subnet. It is the
459 presence of a DMB that makes cross-subnet browsing possible for a workgroup.
461 <a class="indexterm" name="id2548497"></a>
462 In a workgroup environment the DMB must be a Samba server, and there must only be one DMB per workgroup name.
463 To set up a Samba server as a DMB, set the following option in the <em class="parameter"><code>[global]</code></em> section
464 of the <code class="filename">smb.conf</code> file:
466 </p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id2548528"></a><em class="parameter"><code>domain master = yes</code></em></td></tr></table><p>
468 <a class="indexterm" name="id2548544"></a>
469 <a class="indexterm" name="id2548550"></a>
470 The DMB should preferably be the LMB for its own subnet. In order to achieve this, set the following options
471 in the <em class="parameter"><code>[global]</code></em> section of the <code class="filename">smb.conf</code> file as shown in <a href="NetworkBrowsing.html#dmbexample" title="Example 9.1. Domain Master Browser smb.conf">Domain Master Browser smb.conf</a>
472 </p><div class="example"><a name="dmbexample"></a><p class="title"><b>Example 9.1. Domain Master Browser smb.conf</b></p><table class="simplelist" border="0" summary="Simple list"><tr><td> </td></tr><tr><td><em class="parameter"><code>[global]</code></em></td></tr><tr><td><a class="indexterm" name="id2548605"></a><em class="parameter"><code>domain master = yes</code></em></td></tr><tr><td><a class="indexterm" name="id2548617"></a><em class="parameter"><code>local master = yes</code></em></td></tr><tr><td><a class="indexterm" name="id2548630"></a><em class="parameter"><code>preferred master = yes</code></em></td></tr><tr><td><a class="indexterm" name="id2548643"></a><em class="parameter"><code>os level = 65</code></em></td></tr></table></div><p>
473 <a class="indexterm" name="id2548659"></a>
474 <a class="indexterm" name="id2548666"></a>
475 The DMB may be the same machine as the WINS server, if necessary.
477 <a class="indexterm" name="id2548677"></a>
478 <a class="indexterm" name="id2548684"></a>
479 <a class="indexterm" name="id2548690"></a>
480 Next, you should ensure that each of the subnets contains a machine that can act as an LMB for the workgroup.
481 Any MS Windows NT/200x/XP machine should be able to do this, as will Windows 9x/Me machines (although these
482 tend to get rebooted more often, so it is not such a good idea to use them). To make a Samba server an LMB,
483 set the following options in the <em class="parameter"><code>[global]</code></em> section of the <code class="filename">smb.conf</code> file as shown in
484 <a href="NetworkBrowsing.html#lmbexample" title="Example 9.2. Local master browser smb.conf">Local master browser smb.conf</a>
485 </p><div class="example"><a name="lmbexample"></a><p class="title"><b>Example 9.2. Local master browser smb.conf</b></p><table class="simplelist" border="0" summary="Simple list"><tr><td> </td></tr><tr><td><em class="parameter"><code>[global]</code></em></td></tr><tr><td><a class="indexterm" name="id2548748"></a><em class="parameter"><code>domain master = no</code></em></td></tr><tr><td><a class="indexterm" name="id2548761"></a><em class="parameter"><code>local master = yes</code></em></td></tr><tr><td><a class="indexterm" name="id2548773"></a><em class="parameter"><code>preferred master = yes</code></em></td></tr><tr><td><a class="indexterm" name="id2548786"></a><em class="parameter"><code>os level = 65</code></em></td></tr></table></div><p>
486 <a class="indexterm" name="id2548802"></a>
487 Do not do this for more than one Samba server on each subnet, or they will war with
488 each other over which is to be the LMB.
490 <a class="indexterm" name="id2548814"></a>
491 <a class="indexterm" name="id2548821"></a>
492 The <a class="indexterm" name="id2548828"></a>local master parameter allows Samba to act as a
493 LMB. The <a class="indexterm" name="id2548836"></a>preferred master causes <span><strong class="command">nmbd</strong></span>
494 to force a browser election on startup and the <a class="indexterm" name="id2548850"></a>os level
495 parameter sets Samba high enough so it should win any browser elections.
497 <a class="indexterm" name="id2548862"></a>
498 If you have an NT machine on the subnet that you wish to be the LMB, you can disable Samba from
499 becoming an LMB by setting the following options in the <em class="parameter"><code>[global]</code></em> section of the
500 <code class="filename">smb.conf</code> file as shown in <a href="NetworkBrowsing.html#nombexample" title="Example 9.3. smb.conf for Not Being a Master Browser">smb.conf for Not Being a Master Browser</a>.
502 </p><div class="example"><a name="nombexample"></a><p class="title"><b>Example 9.3. smb.conf for Not Being a Master Browser</b></p><table class="simplelist" border="0" summary="Simple list"><tr><td> </td></tr><tr><td><em class="parameter"><code>[global]</code></em></td></tr><tr><td><a class="indexterm" name="id2548918"></a><em class="parameter"><code>domain master = no</code></em></td></tr><tr><td><a class="indexterm" name="id2548931"></a><em class="parameter"><code>local master = no</code></em></td></tr><tr><td><a class="indexterm" name="id2548943"></a><em class="parameter"><code>preferred master = no</code></em></td></tr><tr><td><a class="indexterm" name="id2548956"></a><em class="parameter"><code>os level = 0</code></em></td></tr></table></div><p>
503 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2548972"></a>Domain Browsing Configuration</h3></div></div></div><p>
504 <a class="indexterm" name="id2548980"></a>
505 <a class="indexterm" name="id2548987"></a>
506 <a class="indexterm" name="id2548993"></a>
507 <a class="indexterm" name="id2549000"></a>
508 If you are adding Samba servers to a Windows NT domain, then you must not set up a Samba server as a DMB. By
509 default, a Windows NT PDC for a domain is also the DMB for that domain. Network browsing may break if a Samba
510 server other than the PDC registers the DMB NetBIOS name (<em class="replaceable"><code>DOMAIN</code></em><1B>) with
513 <a class="indexterm" name="id2549019"></a>
514 For subnets other than the one containing the Windows NT PDC, you may set up Samba servers as LMBs as
515 described. To make a Samba server a Local Master Browser, set the following options in the <em class="parameter"><code>[global]</code></em> section of the <code class="filename">smb.conf</code> file as shown in <a href="NetworkBrowsing.html#remsmb" title="Example 9.4. Local Master Browser smb.conf">Local Master Browser
517 </p><div class="example"><a name="remsmb"></a><p class="title"><b>Example 9.4. Local Master Browser smb.conf</b></p><table class="simplelist" border="0" summary="Simple list"><tr><td> </td></tr><tr><td><em class="parameter"><code>[global]</code></em></td></tr><tr><td><a class="indexterm" name="id2549075"></a><em class="parameter"><code>domain master = no</code></em></td></tr><tr><td><a class="indexterm" name="id2549088"></a><em class="parameter"><code>local master = yes</code></em></td></tr><tr><td><a class="indexterm" name="id2549101"></a><em class="parameter"><code>preferred master = yes</code></em></td></tr><tr><td><a class="indexterm" name="id2549114"></a><em class="parameter"><code>os level = 65</code></em></td></tr></table></div><p>
518 <a class="indexterm" name="id2549129"></a>
519 <a class="indexterm" name="id2549136"></a>
520 If you wish to have a Samba server fight the election with machines on the same subnet, you may set the
521 <a class="indexterm" name="id2549145"></a>os level parameter to lower levels. By doing this you can tune the order of machines
522 that will become LMBs if they are running. For more details on this, refer to <a href="NetworkBrowsing.html#browse-force-master" title="Forcing Samba to Be the Master">Forcing Samba to Be the Master</a>.
524 <a class="indexterm" name="id2549167"></a>
525 <a class="indexterm" name="id2549173"></a>
526 <a class="indexterm" name="id2549180"></a>
527 If you have Windows NT machines that are members of the domain on all subnets and you are sure they will
528 always be running, you can disable Samba from taking part in browser elections and ever becoming an LMB by
529 setting the following options in the <em class="parameter"><code>[global]</code></em> section of the <code class="filename">smb.conf</code> file as shown
530 in <a href="NetworkBrowsing.html#xremmb" title="Example 9.5. smb.conf for Not Being a master browser"><code class="filename">smb.conf</code> for Not Being a master browser</a>
532 </p><div class="example"><a name="xremmb"></a><p class="title"><b>Example 9.5. <code class="filename">smb.conf</code> for Not Being a master browser</b></p><em class="parameter"><code>[global]</code></em><a class="indexterm" name="id2549239"></a>domain master = no
533 <a class="indexterm" name="id2549246"></a>local master = no
534 <a class="indexterm" name="id2549253"></a>preferred master = no
535 <a class="indexterm" name="id2549261"></a>os level = 0
537 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="browse-force-master"></a>Forcing Samba to Be the Master</h3></div></div></div><p>
538 <a class="indexterm" name="id2549283"></a>
539 <a class="indexterm" name="id2549290"></a>
540 <a class="indexterm" name="id2549296"></a>
541 <a class="indexterm" name="id2549303"></a>
542 <a class="indexterm" name="id2549310"></a>
543 <a class="indexterm" name="id2549317"></a>
544 <a class="indexterm" name="id2549324"></a>
545 Who becomes the master browser is determined by an election process using broadcasts. Each election packet
546 contains a number of parameters that determine what precedence (bias) a host should have in the election. By
547 default Samba uses a low precedence and thus loses elections to just about every Windows network server or
550 If you want Samba to win elections, set the <a class="indexterm" name="id2549340"></a>os level global option in <code class="filename">smb.conf</code> to a
551 higher number. It defaults to 20. Using 34 would make it win all elections over every other system (except
552 other Samba systems).
554 An <a class="indexterm" name="id2549359"></a>os level of two would make it beat Windows for Workgroups and Windows 9x/Me, but
555 not MS Windows NT/200x Server. An MS Windows NT/200x Server domain controller uses level 32. The maximum os
558 <a class="indexterm" name="id2549373"></a>
559 <a class="indexterm" name="id2549380"></a>
560 <a class="indexterm" name="id2549387"></a>
561 <a class="indexterm" name="id2549394"></a>
562 If you want Samba to force an election on startup, set the <a class="indexterm" name="id2549402"></a>preferred master global
563 option in <code class="filename">smb.conf</code> to <code class="constant">yes</code>. Samba will then have a slight advantage over other
564 potential master browsers that are not preferred master browsers. Use this parameter with care, because if
565 you have two hosts (whether they are Windows 9x/Me or NT/200x/XP or Samba) on the same local subnet both set
566 with <a class="indexterm" name="id2549423"></a>preferred master to <code class="constant">yes</code>, then periodically and continually
567 they will force an election in order to become the LMB.
569 <a class="indexterm" name="id2549439"></a>
570 <a class="indexterm" name="id2549445"></a>
571 <a class="indexterm" name="id2549452"></a>
572 <a class="indexterm" name="id2549459"></a>
573 <a class="indexterm" name="id2549465"></a>
574 If you want Samba to be a <span class="emphasis"><em>DMB</em></span>, then it is recommended that you also set <a class="indexterm" name="id2549477"></a>preferred master to <code class="constant">yes</code>, because Samba will not become a DMB for the whole of
575 your LAN or WAN if it is not also a LMB on its own broadcast isolated subnet.
577 <a class="indexterm" name="id2549493"></a>
578 <a class="indexterm" name="id2549500"></a>
579 <a class="indexterm" name="id2549507"></a>
580 <a class="indexterm" name="id2549513"></a>
581 <a class="indexterm" name="id2549520"></a>
582 It is possible to configure two Samba servers to attempt to become the DMB for a domain. The first server that
583 comes up will be the DMB. All other Samba servers will attempt to become the DMB every 5 minutes. They will
584 find that another Samba server is already the DMB and will fail. This provides automatic redundancy should the
585 current DMB fail. The network bandwidth overhead of browser elections is relatively small, requiring
586 approximately four UDP packets per machine per election. The maximum size of a UDP packet is 576 bytes.
587 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2549538"></a>Making Samba the Domain Master</h3></div></div></div><p>
588 <a class="indexterm" name="id2549546"></a>
589 <a class="indexterm" name="id2549553"></a>
590 <a class="indexterm" name="id2549560"></a>
591 <a class="indexterm" name="id2549567"></a>
592 The domain master browser is responsible for collating the browse lists of multiple subnets so browsing can
593 occur between subnets. You can make Samba act as the domain master browser by setting <a class="indexterm" name="id2549577"></a>domain master = yes in <code class="filename">smb.conf</code>. By default it will not be a domain master browser.
595 <a class="indexterm" name="id2549594"></a>
596 <a class="indexterm" name="id2549601"></a>
597 Do not set Samba to be the domain master for a workgroup that has the same name as an NT/200x domain. If
598 Samba is configured to be the domain master for a workgroup that is present on the same network as a Windows
599 NT/200x domain that has the same name, network browsing problems will certainly be experienced.
601 When Samba is the domain master and the master browser, it will listen for master announcements (made roughly
602 every 12 minutes) from LMBs on other subnets and then contact them to synchronize browse lists.
604 <a class="indexterm" name="id2549624"></a>
605 <a class="indexterm" name="id2549630"></a>
606 If you want Samba to be the domain master, you should also set the <a class="indexterm" name="id2549639"></a>os level high
607 enough to make sure it wins elections, and set <a class="indexterm" name="id2549647"></a>preferred master to
608 <code class="constant">yes</code>, to get Samba to force an election on startup.
610 <a class="indexterm" name="id2549662"></a>
611 <a class="indexterm" name="id2549668"></a>
612 All servers (including Samba) and clients should be using a WINS server to resolve NetBIOS names. If your
613 clients are only using broadcasting to resolve NetBIOS names, then two things will occur:
614 </p><div class="orderedlist"><ol type="1"><li><p>
615 <a class="indexterm" name="id2549691"></a>
616 <a class="indexterm" name="id2549697"></a>
617 LMBs will be unable to find a DMB because they will be looking only on the local subnet.
619 <a class="indexterm" name="id2549712"></a>
620 If a client happens to get hold of a domain-wide browse list and a user attempts to access a
621 host in that list, it will be unable to resolve the NetBIOS name of that host.
622 </p></li></ol></div><p>
623 <a class="indexterm" name="id2549728"></a>
624 If, however, both Samba and your clients are using a WINS server, then:
625 </p><div class="orderedlist"><ol type="1"><li><p>
626 LMBs will contact the WINS server and, as long as Samba has registered that it is a DMB with the WINS
627 server, the LMB will receive Samba's IP address as its DMB.
629 When a client receives a domain-wide browse list and a user attempts to access a host in that list, it will
630 contact the WINS server to resolve the NetBIOS name of that host. As long as that host has registered its
631 NetBIOS name with the same WINS server, the user will be able to see that host..
632 </p></li></ol></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2549766"></a>Note about Broadcast Addresses</h3></div></div></div><p>
633 <a class="indexterm" name="id2549775"></a>
634 If your network uses a zero-based broadcast address (for example, if it ends in a 0), then you will strike problems. Windows for Workgroups
635 does not seem to support a zeros broadcast, and you will probably find that browsing and name lookups will not work.
636 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2549788"></a>Multiple Interfaces</h3></div></div></div><p>
637 <a class="indexterm" name="id2549796"></a>
638 Samba supports machines with multiple network interfaces. If you have multiple interfaces, you will
639 need to use the <a class="indexterm" name="id2549805"></a>interfaces option in <code class="filename">smb.conf</code> to configure them. For example, the
640 machine you are working with has 4 network interfaces; <code class="literal">eth0</code>, <code class="literal">eth1</code>,
641 <code class="literal">eth2</code>, <code class="literal">eth3</code> and only interfaces <code class="literal">eth1</code> and
642 <code class="literal">eth4</code> should be used by Samba. In this case, the following <code class="filename">smb.conf</code> file entries would
644 </p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id2549868"></a><em class="parameter"><code>interfaces = eth1, eth4</code></em></td></tr><tr><td><a class="indexterm" name="id2549881"></a><em class="parameter"><code>bind interfaces only = Yes</code></em></td></tr></table><p>
645 <a class="indexterm" name="id2549894"></a>
646 <a class="indexterm" name="id2549901"></a>
647 <a class="indexterm" name="id2549908"></a>
648 <a class="indexterm" name="id2549915"></a>
649 <a class="indexterm" name="id2549921"></a>
650 <a class="indexterm" name="id2549928"></a>
651 <a class="indexterm" name="id2549935"></a>
652 The <a class="indexterm" name="id2549942"></a>bind interfaces only = Yes is necessary to exclude TCP/IP session
653 services (ports 135, 139, and 445) over the interfaces that are not specified. Please be aware that
654 <span><strong class="command">nmbd</strong></span> will listen for incoming UDP port 137 packets on the unlisted interfaces, but it will
655 not answer them. It will, however, send its broadcast packets over the unlisted interfaces. Total isolation of
656 ethernet interface requires the use of a firewall to block ports 137 and 138 (UDP), and ports 135, 139, and
657 445 (TCP) on all network interfaces that must not be able to access the Samba server.
658 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2549966"></a>Use of the Remote Announce Parameter</h3></div></div></div><p>
659 The <a class="indexterm" name="id2549975"></a>remote announce parameter of
660 <code class="filename">smb.conf</code> can be used to forcibly ensure
661 that all the NetBIOS names on a network get announced to a remote network.
662 The syntax of the <a class="indexterm" name="id2549990"></a>remote announce parameter is:
663 </p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id2550003"></a><em class="parameter"><code>remote announce = 192.168.12.23 [172.16.21.255] ...</code></em></td></tr></table><p>
664 <span class="emphasis"><em>or</em></span>
665 </p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id2550025"></a><em class="parameter"><code>remote announce = 192.168.12.23/MIDEARTH [172.16.21.255/ELVINDORF] ...</code></em></td></tr></table><p>
668 </p><div class="variablelist"><dl><dt><span class="term"><em class="replaceable"><code>192.168.12.23</code></em> and <em class="replaceable"><code>172.16.21.255</code></em></span></dt><dd><p>
669 <a class="indexterm" name="id2550054"></a>
670 <a class="indexterm" name="id2550063"></a>
671 is either the LMB IP address or the broadcast address of the remote network.
672 That is, the LMB is at 192.168.1.23, or the address could be given as 172.16.21.255 where the netmask
673 is assumed to be 24 bits (255.255.255.0). When the remote announcement is made to the broadcast
674 address of the remote network, every host will receive our announcements. This is noisy and therefore
675 undesirable but may be necessary if we do not know the IP address of the remote LMB.
676 </p></dd><dt><span class="term"><em class="replaceable"><code>WORKGROUP</code></em></span></dt><dd><p>is optional and can be either our own workgroup or that of the remote network. If you use the
677 workgroup name of the remote network, our NetBIOS machine names will end up looking like
678 they belong to that workgroup. This may cause name resolution problems and should be avoided.
679 </p></dd></dl></div><p>
680 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2550101"></a>Use of the Remote Browse Sync Parameter</h3></div></div></div><p>
681 <a class="indexterm" name="id2550109"></a>
682 <a class="indexterm" name="id2550115"></a>
683 The <a class="indexterm" name="id2550122"></a>remote browse sync parameter of <code class="filename">smb.conf</code> is used to announce to another LMB that
684 it must synchronize its NetBIOS name list with our Samba LMB. This works only if the Samba server that has
685 this option is simultaneously the LMB on its network segment.
687 The syntax of the <a class="indexterm" name="id2550143"></a>remote browse sync parameter is:
689 </p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id2550156"></a><em class="parameter"><code>remote browse sync</code></em></td></tr></table><p>
690 <a class="indexterm" name="id2550169"></a>
691 <a class="indexterm" name="id2550175"></a>
692 where <em class="replaceable"><code>192.168.10.40</code></em> is either the IP address of the
693 remote LMB or the network broadcast address of the remote segment.
694 </p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2550191"></a>WINS: The Windows Internetworking Name Server</h2></div></div></div><p>
695 <a class="indexterm" name="id2550200"></a>
696 <a class="indexterm" name="id2550206"></a>
697 <a class="indexterm" name="id2550213"></a>
698 Use of WINS (either Samba WINS or MS Windows NT Server WINS) is highly
699 recommended. Every NetBIOS machine registers its name together with a
700 name_type value for each of several types of service it has available.
701 It registers its name directly as a unique (the type 0x03) name.
702 It also registers its name if it is running the LanManager-compatible
703 server service (used to make shares and printers available to other users)
704 by registering the server (the type 0x20) name.
706 <a class="indexterm" name="id2550232"></a>
707 <a class="indexterm" name="id2550238"></a>
708 All NetBIOS names are up to 15 characters in length. The name_type variable
709 is added to the end of the name, thus creating a 16 character name. Any
710 name that is shorter than 15 characters is padded with spaces to the 15th
711 character. Thus, all NetBIOS names are 16 characters long (including the
712 name_type information).
714 <a class="indexterm" name="id2550254"></a>
715 <a class="indexterm" name="id2550261"></a>
716 <a class="indexterm" name="id2550268"></a>
717 <a class="indexterm" name="id2550274"></a>
718 WINS can store these 16-character names as they get registered. A client
719 that wants to log onto the network can ask the WINS server for a list
720 of all names that have registered the NetLogon service name_type. This saves
721 broadcast traffic and greatly expedites logon processing. Since broadcast
722 name resolution cannot be used across network segments, this type of
723 information can only be provided via WINS or via a statically configured
724 <code class="filename">lmhosts</code> file that must reside on all clients in the
727 <a class="indexterm" name="id2550299"></a>
728 <a class="indexterm" name="id2550306"></a>
729 <a class="indexterm" name="id2550312"></a>
730 <a class="indexterm" name="id2550319"></a>
731 <a class="indexterm" name="id2550326"></a>
732 WINS also forces browse list synchronization by all LMBs. LMBs must synchronize their browse list with the
733 DMB, and WINS helps the LMB to identify its DMB. By definition this will work only within a single workgroup.
734 Note that the DMB has nothing to do with what is referred to as an MS Windows NT domain. The latter is a
735 reference to a security environment, while the DMB refers to the master controller for browse list information
738 <a class="indexterm" name="id2550343"></a>
739 <a class="indexterm" name="id2550350"></a>
740 <a class="indexterm" name="id2550357"></a>
741 <a class="indexterm" name="id2550364"></a>
742 WINS will work correctly only if every client TCP/IP protocol stack
743 is configured to use the WINS servers. Any client that is not
744 configured to use the WINS server will continue to use only broadcast-based
745 name registration, so WINS may never get to know about it. In any case,
746 machines that have not registered with a WINS server will fail name-to-address
747 lookup attempts by other clients and will therefore cause workstation access
750 To configure Samba as a WINS server, just add
751 <a class="indexterm" name="id2550382"></a>wins support = yes to the <code class="filename">smb.conf</code>
752 file [global] section.
754 To configure Samba to register with a WINS server, just add <a class="indexterm" name="id2550401"></a>wins server = 10.0.0.18 to your <code class="filename">smb.conf</code> file <em class="parameter"><code>[global]</code></em> section.
755 </p><div class="important" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Important</h3><p>
756 Never use <a class="indexterm" name="id2550425"></a>wins support = yes together with <a class="indexterm" name="id2550432"></a>wins server = 10.0.0.18 particularly not using its own IP address. Specifying both will cause <span class="application">nmbd</span>
758 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2550448"></a>WINS Server Configuration</h3></div></div></div><p>
759 <a class="indexterm" name="id2550456"></a>
760 Either a Samba server or a Windows NT server machine may be set up
761 as a WINS server. To configure a Samba server to be a WINS server, you must
762 add to the <code class="filename">smb.conf</code> file on the selected Server the following line to
763 the <em class="parameter"><code>[global]</code></em> section:
765 </p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id2550487"></a><em class="parameter"><code>wins support = yes</code></em></td></tr></table><p>
767 <a class="indexterm" name="id2550503"></a>
768 Versions of Samba prior to 1.9.17 had this parameter default to
769 yes. If you have any older versions of Samba on your network, it is
770 strongly suggested you upgrade to a recent version, or at the very
771 least set the parameter to “<span class="quote">no</span>” on all these machines.
773 Machines configured with <a class="indexterm" name="id2550521"></a>wins support = yes will keep a list of
774 all NetBIOS names registered with them, acting as a DNS for NetBIOS names.
776 <a class="indexterm" name="id2550533"></a>
777 It is strongly recommended to set up only one WINS server. Do not set the
778 <a class="indexterm" name="id2550542"></a>wins support = yes option on more than one Samba
781 <a class="indexterm" name="id2550553"></a>
782 <a class="indexterm" name="id2550562"></a>
783 <a class="indexterm" name="id2550569"></a>
784 <a class="indexterm" name="id2550576"></a>
785 <a class="indexterm" name="id2550583"></a>
786 To configure Windows NT/200x Server as a WINS server, install and configure the WINS service. See the Windows
787 NT/200x documentation for details. Windows NT/200x WINS servers can replicate to each other, allowing more
788 than one to be set up in a complex subnet environment. Because Microsoft refuses to document the replication
789 protocols, Samba cannot currently participate in these replications. It is possible that a Samba-to-Samba WINS
790 replication protocol may be defined in the future, in which case more than one Samba machine could be set up
791 as a WINS server. Currently only one Samba server should have the <a class="indexterm" name="id2550601"></a>wins support = yes parameter set.
793 <a class="indexterm" name="id2550611"></a>
794 <a class="indexterm" name="id2550618"></a>
795 After the WINS server has been configured, you must ensure that all machines participating on the network are
796 configured with the address of this WINS server. If your WINS server is a Samba machine, fill in the Samba
797 machine IP address in the <span class="guilabel">Primary WINS Server</span> field of the <span class="guilabel">Control
798 Panel->Network->Protocols->TCP->WINS Server</span> dialogs in Windows 9x/Me or Windows NT/200x. To tell a
799 Samba server the IP address of the WINS server, add the following line to the <em class="parameter"><code>[global]</code></em> section of all <code class="filename">smb.conf</code> files:
800 </p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id2550663"></a><em class="parameter"><code>wins server = <name or IP address></code></em></td></tr></table><p>
801 where <name or IP address> is either the DNS name of the WINS server
802 machine or its IP address.
804 This line must not be set in the <code class="filename">smb.conf</code> file of the Samba
805 server acting as the WINS server itself. If you set both the
806 <a class="indexterm" name="id2550692"></a>wins support = yes option and the
807 <a class="indexterm" name="id2550700"></a>wins server = <name> option then
808 <span><strong class="command">nmbd</strong></span> will fail to start.
810 <a class="indexterm" name="id2550718"></a>
811 <a class="indexterm" name="id2550725"></a>
812 <a class="indexterm" name="id2550732"></a>
813 <a class="indexterm" name="id2550739"></a>
814 There are two possible scenarios for setting up cross-subnet browsing.
815 The first details setting up cross-subnet browsing on a network containing
816 Windows 9x/Me, Samba, and Windows NT/200x machines that are not configured as
817 part of a Windows NT domain. The second details setting up cross-subnet
818 browsing on networks that contain NT domains.
819 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2550754"></a>WINS Replication</h3></div></div></div><p>
820 <a class="indexterm" name="id2550762"></a>
821 <a class="indexterm" name="id2550771"></a>
822 Samba-3 permits WINS replication through the use of the <code class="filename">wrepld</code> utility. This tool is not
823 currently in use because it is still in development and has not been worked on for a long time. As soon as
824 this tool becomes moderately functional, we will prepare man pages and enhance this section of the
825 documentation to provide usage and technical details.
826 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2550792"></a>Static WINS Entries</h3></div></div></div><p>
827 <a class="indexterm" name="id2550800"></a>
828 <a class="indexterm" name="id2550806"></a>
829 <a class="indexterm" name="id2550813"></a>
830 <a class="indexterm" name="id2550820"></a>
831 Adding static entries to your Samba WINS server is actually fairly easy. All you have to do is add a line to
832 <code class="filename">wins.dat</code>, typically located in <code class="filename">/usr/local/samba/var/locks</code> or <code class="filename">/var/run/samba</code>.
834 Entries in <code class="filename">wins.dat</code> take the form of:
835 </p><pre class="programlisting">
836 "NAME#TYPE" TTL ADDRESS+ FLAGS
838 <a class="indexterm" name="id2550866"></a>
839 <a class="indexterm" name="id2550872"></a>
840 where NAME is the NetBIOS name, TYPE is the NetBIOS type, TTL is the time-to-live as an absolute time in
841 seconds, ADDRESS+ is one or more addresses corresponding to the registration, and FLAGS are the NetBIOS flags
842 for the registration.
843 </p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
844 A change that has been made to the <code class="filename">wins.dat</code> will not take effect until <span class="application">nmbd</span> has been
845 restarted. It should be noted that since the <code class="filename">wins.dat</code> file changes dynamically, <span class="application">nmbd</span>
846 should be stopped before editting this file. Do not forget to restart <span class="application">nmbd</span> when this file has been editted.
848 A typical dynamic entry looks like this:
849 </p><pre class="programlisting">
850 "MADMAN#03" 1155298378 192.168.1.2 66R
852 To make a NetBIOS name static (permanent), simply set the TTL to 0, like this:
853 </p><pre class="programlisting">
854 "MADMAN#03" 0 192.168.1.2 66R
857 <a class="indexterm" name="id2550945"></a>
858 <a class="indexterm" name="id2550952"></a>
859 <a class="indexterm" name="id2550959"></a>
860 <a class="indexterm" name="id2550966"></a>
861 <a class="indexterm" name="id2550972"></a>
862 <a class="indexterm" name="id2550979"></a>
863 <a class="indexterm" name="id2550986"></a>
864 The NetBIOS flags may be interpreted as additive hexadecimal values: 00 - Broadcast node registration, 20 -
865 Peer node registration, 40 - Meta node registration, 60 - Hybrid node registration, 02 - Permanent name, 04 -
866 Active name, 80 - Group name. The 'R' indicates this is a registration record. Thus 66R means: Hybrid node
867 active and permanent NetBIOS name. These values may be found in the <code class="filename">nameserv.h</code> header
868 file from the Samba source code repository. These are the values for the NB flags.
870 <a class="indexterm" name="id2551010"></a>
871 Though this method works with early Samba-3 versions, there is a possibility that it may change in future
872 versions if WINS replication is added.
873 </p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2551023"></a>Helpful Hints</h2></div></div></div><p>
874 The following hints should be carefully considered because they are stumbling points
875 for many new network administrators.
876 </p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2551034"></a>Windows Networking Protocols</h3></div></div></div><p>
877 <a class="indexterm" name="id2551042"></a>
878 <a class="indexterm" name="id2551049"></a>
879 A common cause of browsing problems results from the installation of more than one protocol on an MS Windows
881 </p><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p>
882 Do not use more than one protocol on MS Windows clients.
884 <a class="indexterm" name="id2551067"></a>
885 <a class="indexterm" name="id2551073"></a>
886 Every NetBIOS machine takes part in a process of electing the LMB (and DMB)
887 every 15 minutes. A set of election criteria is used to determine the order
888 of precedence for winning this election process. A machine running Samba or
889 Windows NT will be biased, so the most suitable machine will predictably
890 win and thus retain its role.
892 <a class="indexterm" name="id2551089"></a>
893 <a class="indexterm" name="id2551096"></a>
894 <a class="indexterm" name="id2551103"></a>
895 <a class="indexterm" name="id2551109"></a>
896 <a class="indexterm" name="id2551116"></a>
897 <a class="indexterm" name="id2551123"></a>
898 The election process is <span class="emphasis"><em>fought out, so to speak</em></span> over every NetBIOS network interface. In
899 the case of a Windows 9x/Me machine that has both TCP/IP and IPX installed and has NetBIOS enabled over both
900 protocols, the election will be decided over both protocols. As often happens, if the Windows 9x/Me machine is
901 the only one with both protocols, then the LMB may be won on the NetBIOS interface over the IPX protocol.
902 Samba will then lose the LMB role because Windows 9x/Me will insist it knows who the LMB is. Samba will then
903 cease to function as an LMB, and browse list operation on all TCP/IP-only machines will therefore fail.
905 <a class="indexterm" name="id2551156"></a>
906 <a class="indexterm" name="id2551163"></a>
907 Windows 95, 98, 98se, and Me are referred to generically as Windows 9x/Me.
908 The Windows NT4, 200x, and XP use common protocols. These are roughly
909 referred to as the Windows NT family, but it should be recognized that 2000 and
910 XP/2003 introduce new protocol extensions that cause them to behave
911 differently from MS Windows NT4. Generally, where a server does not support
912 the newer or extended protocol, these will fall back to the NT4 protocols.
914 The safest rule of all to follow is: Use only one protocol!
915 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2551184"></a>Name Resolution Order</h3></div></div></div><p>
916 <a class="indexterm" name="id2551192"></a>
917 <a class="indexterm" name="id2551199"></a>
918 Resolution of NetBIOS names to IP addresses can take place using a number
919 of methods. The only ones that can provide NetBIOS name_type information
921 </p><div class="itemizedlist"><ul type="disc"><li><p>WINS the best tool.</p></li><li><p>LMHOSTS static and hard to maintain.</p></li><li><p>Broadcast uses UDP and cannot resolve names across remote segments.</p></li></ul></div><p>
922 Alternative means of name resolution include:
923 </p><div class="itemizedlist"><ul type="disc"><li><p>Static <code class="filename">/etc/hosts</code> hard to maintain and lacks name_type info.</p></li><li><p>DNS is a good choice but lacks essential NetBIOS name_type information.</p></li></ul></div><p>
924 <a class="indexterm" name="id2551268"></a>
925 <a class="indexterm" name="id2551274"></a>
926 Many sites want to restrict DNS lookups and avoid broadcast name
927 resolution traffic. The <em class="parameter"><code>name resolve order</code></em> parameter is of great help here.
928 The syntax of the <em class="parameter"><code>name resolve order</code></em> parameter is:
929 </p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id2551302"></a><em class="parameter"><code>name resolve order = wins lmhosts bcast host</code></em></td></tr></table><p>
930 <span class="emphasis"><em>or</em></span>
931 </p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id2551324"></a><em class="parameter"><code>name resolve order = wins lmhosts (eliminates bcast and host)</code></em></td></tr></table><p>
933 </p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id2551343"></a><em class="parameter"><code>name resolve order = host lmhost wins bcast</code></em></td></tr></table><p>
934 <a class="indexterm" name="id2551356"></a>
935 where “<span class="quote">host</span>” refers to the native methods used by the UNIX system to implement the
936 gethostbyname() function call. This is normally controlled by <code class="filename">/etc/host.conf</code>,
937 <code class="filename">/etc/nsswitch.conf</code> and <code class="filename">/etc/resolv.conf</code>.
938 </p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2551391"></a>Technical Overview of Browsing</h2></div></div></div><p>
939 <a class="indexterm" name="id2551399"></a>
940 SMB networking provides a mechanism by which clients can access a list
941 of machines in a network called <a class="indexterm" name="id2551407"></a>browse list. This list
942 contains machines that are ready to offer file and/or print services
943 to other machines within the network. It therefore does not include
944 machines that aren't currently able to do server tasks. The browse
945 list is heavily used by all SMB clients. Configuration of SMB
946 browsing has been problematic for some Samba users, hence this
949 <a class="indexterm" name="id2551423"></a>
950 <a class="indexterm" name="id2551430"></a>
951 <a class="indexterm" name="id2551437"></a>
952 MS Windows 2000 and later versions, as with Samba-3 and later versions, can be
953 configured to not use NetBIOS over TCP/IP. When configured this way,
954 it is imperative that name resolution (using DNS/LDAP/ADS) be correctly
955 configured and operative. Browsing will not work if name resolution
956 from SMB machine names to IP addresses does not function correctly.
958 <a class="indexterm" name="id2551454"></a>
959 <a class="indexterm" name="id2551460"></a>
960 Where NetBIOS over TCP/IP is enabled, use of a WINS server is highly
961 recommended to aid the resolution of NetBIOS (SMB) names to IP addresses.
962 WINS allows remote segment clients to obtain NetBIOS name_type information
963 that cannot be provided by any other means of name resolution.
964 </p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2551473"></a>Browsing Support in Samba</h3></div></div></div><p>
965 <a class="indexterm" name="id2551481"></a>
966 <a class="indexterm" name="id2551488"></a>
967 <a class="indexterm" name="id2551494"></a>
968 <a class="indexterm" name="id2551501"></a>
969 Samba facilitates browsing. The browsing is supported by <span class="application">nmbd</span>
970 and is also controlled by options in the <code class="filename">smb.conf</code> file.
971 Samba can act as an LMB for a workgroup, and the ability
972 to support domain logons and scripts is now available.
974 <a class="indexterm" name="id2551527"></a>
975 <a class="indexterm" name="id2551534"></a>
976 <a class="indexterm" name="id2551540"></a>
977 Samba can also act as a DMB for a workgroup. This
978 means that it will collate lists from LMBs into a
979 wide-area network server list. In order for browse clients to
980 resolve the names they may find in this list, it is recommended that
981 both Samba and your clients use a WINS server.
983 <a class="indexterm" name="id2551555"></a>
984 Do not set Samba to be the domain master for a workgroup that has the same
985 name as an NT Domain. On each wide-area network, you must only ever have one
986 DMB per workgroup, regardless of whether it is NT, Samba,
987 or any other type of domain master that is providing this service.
988 </p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
989 <a class="indexterm" name="id2551571"></a>
990 <a class="indexterm" name="id2551578"></a>
991 <span><strong class="command">nmbd</strong></span> can be configured as a WINS server, but it is not
992 necessary to specifically use Samba as your WINS server. MS Windows
993 NT4, Server or Advanced Server 200x can be configured as
994 your WINS server. In a mixed NT/200x server and Samba environment on
995 a WAN, it is recommended that you use the Microsoft
996 WINS server capabilities. In a Samba-only environment, it is
997 recommended that you use one and only one Samba server as the WINS server.
999 <a class="indexterm" name="id2551601"></a>
1000 To get browsing to work, you need to run <span><strong class="command">nmbd</strong></span> as usual, but must
1001 use the <a class="indexterm" name="id2551615"></a>workgroup option in <code class="filename">smb.conf</code>
1002 to control what workgroup Samba becomes a part of.
1004 <a class="indexterm" name="id2551632"></a>
1005 Samba also has a useful option for a Samba server to offer itself for
1006 browsing on another subnet. It is recommended that this option is
1007 used only for “<span class="quote">unusual</span>” purposes: announcements over the Internet, for
1008 example. See <a class="indexterm" name="id2551647"></a>remote announce in the
1009 <code class="filename">smb.conf</code> man page.
1010 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2551662"></a>Problem Resolution</h3></div></div></div><p>
1011 <a class="indexterm" name="id2551670"></a>
1012 <a class="indexterm" name="id2551677"></a>
1013 If something does not work, the <code class="filename">log.nmbd</code> file will help
1014 to track down the problem. Try a <a class="indexterm" name="id2551691"></a>log level of 2 or 3 for finding
1015 problems. Also note that the current browse list usually gets stored
1016 in text form in a file called <code class="filename">browse.dat</code>.
1018 <a class="indexterm" name="id2551709"></a>
1019 <a class="indexterm" name="id2551716"></a>
1020 If it does not work, you should still be able to
1021 type the server name as <code class="filename">\\SERVER</code> in <span><strong class="command">filemanager</strong></span>, then
1022 press enter, and <span><strong class="command">filemanager</strong></span> should display the list of available shares.
1024 <a class="indexterm" name="id2551746"></a>
1025 <a class="indexterm" name="id2551753"></a>
1026 Some people find browsing fails because they do not have the global
1027 <a class="indexterm" name="id2551761"></a>guest account set to a valid account. Remember that the
1028 IPC$ connection that lists the shares is done as guest and so you must have a valid guest account.
1029 </p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
1030 <a class="indexterm" name="id2551775"></a>
1031 <a class="indexterm" name="id2551782"></a>
1032 <a class="indexterm" name="id2551789"></a>
1033 <a class="indexterm" name="id2551796"></a>
1034 <a class="indexterm" name="id2551803"></a>
1035 The <code class="literal">IPC$</code> share is used by all SMB/CIFS clients to obtain the list of resources
1036 that is available on the server. This is the source of the list of shares and printers when browsing
1037 an SMB/CIFS server (also Windows machines) using the Windows Explorer to browse resources through
1038 the Windows Network Neighborhood (also called My Network Places) through to a Windows server. At
1039 this point, the client has opened a connection to the <code class="literal">\\server\IPC4</code> resource.
1040 Clicking on a share will then open up a connection to the <code class="literal">\\server\share</code>.
1042 <a class="indexterm" name="id2551839"></a>
1043 <a class="indexterm" name="id2551846"></a>
1044 <a class="indexterm" name="id2551853"></a>
1045 <a class="indexterm" name="id2551860"></a>
1046 MS Windows 2000 and later (as with Samba) can be configured to disallow
1047 anonymous (i.e., guest account) access to the IPC$ share. In that case, the
1048 MS Windows 2000/XP/2003 machine acting as an SMB/CIFS client will use the
1049 name of the currently logged-in user to query the IPC$ share. MS Windows
1050 9x/Me clients are not able to do this and thus will not be able to browse
1053 <a class="indexterm" name="id2551877"></a>
1054 The other big problem people have is that their broadcast address,
1055 netmask, or IP address is wrong (specified with the <a class="indexterm" name="id2551886"></a>interfaces option
1056 in <code class="filename">smb.conf</code>)
1057 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2551901"></a>Cross-Subnet Browsing</h3></div></div></div><p>
1058 <a class="indexterm" name="id2551909"></a>
1059 <a class="indexterm" name="id2551918"></a>
1060 Since the release of Samba 1.9.17 (alpha1), Samba has supported the replication of browse lists across subnet
1061 boundaries. This section describes how to set this feature up in different settings.
1063 <a class="indexterm" name="id2551932"></a>
1064 <a class="indexterm" name="id2551939"></a>
1065 <a class="indexterm" name="id2551946"></a>
1066 <a class="indexterm" name="id2551953"></a>
1067 <a class="indexterm" name="id2551959"></a>
1068 <a class="indexterm" name="id2551966"></a>
1069 To see browse lists that span TCP/IP subnets (i.e., networks separated by routers that do not pass broadcast
1070 traffic), you must set up at least one WINS server. The WINS server acts as a DNS for NetBIOS names. This will
1071 allow NetBIOS name-to-IP address translation to be completed by a direct query of the WINS server. This is
1072 done via a directed UDP packet on port 137 to the WINS server machine. The WINS server avoids the necessity of
1073 default NetBIOS name-to-IP address translation, which is done using UDP broadcasts from the querying machine.
1074 This means that machines on one subnet will not be able to resolve the names of machines on another subnet
1075 without using a WINS server. The Samba hacks, <em class="parameter"><code>remote browse sync</code></em>, and <em class="parameter"><code>remote
1076 announce</code></em> are designed to get around the natural limitations that prevent UDP broadcast
1077 propagation. The hacks are not a universal solution and they should not be used in place of WINS, they are
1078 considered last resort methods.
1080 <a class="indexterm" name="id2552004"></a>
1081 <a class="indexterm" name="id2552011"></a>
1082 <a class="indexterm" name="id2552018"></a>
1083 <a class="indexterm" name="id2552025"></a>
1084 Remember, for browsing across subnets to work correctly, all machines, be they Windows 95, Windows NT, or
1085 Samba servers, must have the IP address of a WINS server given to them by a DHCP server or by manual
1086 configuration: for Windows 9x/Me and Windows NT/200x/XP, this is in the TCP/IP Properties, under Network
1087 settings; for Samba, this is in the <code class="filename">smb.conf</code> file.
1089 <a class="indexterm" name="id2552047"></a>
1090 <a class="indexterm" name="id2552054"></a>
1091 <a class="indexterm" name="id2552060"></a>
1092 It is possible to operate Samba-3 without NetBIOS over TCP/IP. If you do this, be warned that if used outside
1093 of MS ADS, this will forgo network browsing support. ADS permits network browsing support through DNS,
1094 providing appropriate DNS records are inserted for all Samba servers.
1095 </p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2552073"></a>Behavior of Cross-Subnet Browsing</h4></div></div></div><p>
1096 <a class="indexterm" name="id2552081"></a>
1097 <a class="indexterm" name="id2552088"></a>
1098 Cross-subnet browsing is a complicated dance, containing multiple moving parts. It has taken Microsoft several
1099 years to get the code that correctly achieves this, and Samba lags behind in some areas. Samba is capable of
1100 cross-subnet browsing when configured correctly.
1102 Consider a network set up as in <a href="NetworkBrowsing.html#browsing1" title="Figure 9.1. Cross-Subnet Browsing Example.">Cross-Subnet Browsing Example</a>.
1103 </p><div class="figure"><a name="browsing1"></a><p class="title"><b>Figure 9.1. Cross-Subnet Browsing Example.</b></p><div class="mediaobject"><img src="images/browsing1.png" width="216" alt="Cross-Subnet Browsing Example."></div></div><p>
1104 <a class="indexterm" name="id2552156"></a>
1105 <a class="indexterm" name="id2552162"></a>
1106 <a class="indexterm" name="id2552169"></a>
1107 This consists of three subnets (1, 2, 3) connected by two routers (R1, R2), which do not pass broadcasts.
1108 Subnet 1 has five machines on it, subnet 2 has four machines, and subnet 3 has four machines. Assume for the
1109 moment that all machines are configured to be in the same workgroup (for simplicity's sake). Machine N1_C on
1110 subnet 1 is configured as the DMB (i.e., it will collate the browse lists for the workgroup). Machine N2_D is
1111 configured as a WINS server, and all the other machines are configured to register their NetBIOS names with
1114 <a class="indexterm" name="id2552188"></a>
1115 <a class="indexterm" name="id2552195"></a>
1116 <a class="indexterm" name="id2552202"></a>
1117 As these machines are booted up, elections for master browsers
1118 take place on each of the three subnets. Assume that machine
1119 N1_C wins on subnet 1, N2_B wins on subnet 2, and N3_D wins on
1120 subnet 3. These machines are known as LMBs for
1121 their particular subnet. N1_C has an advantage in winning as the
1122 LMB on subnet 1 because it is set up as DMB.
1124 <a class="indexterm" name="id2552217"></a>
1125 <a class="indexterm" name="id2552224"></a>
1126 On each of the three networks, machines that are configured to
1127 offer sharing services will broadcast that they are offering
1128 these services. The LMB on each subnet will
1129 receive these broadcasts and keep a record of the fact that
1130 the machine is offering a service. This list of records is
1131 the basis of the browse list. For this case, assume that
1132 all the machines are configured to offer services, so all machines
1133 will be on the browse list.
1135 <a class="indexterm" name="id2552241"></a>
1136 <a class="indexterm" name="id2552248"></a>
1137 <a class="indexterm" name="id2552255"></a>
1138 <a class="indexterm" name="id2552261"></a>
1139 <a class="indexterm" name="id2552268"></a>
1140 For each network, the LMB on that network is
1141 considered <span class="emphasis"><em>authoritative</em></span> for all the names it receives via
1142 local broadcast. This is because a machine seen by the LMB
1143 via a local broadcast must be on the same network as the
1144 Local Master Browser and thus is a <span class="emphasis"><em>trusted</em></span>
1145 and <span class="emphasis"><em>verifiable</em></span> resource. Machines on other networks that
1146 the LMBs learn about when collating their
1147 browse lists have not been directly seen. These records are
1148 called <span class="emphasis"><em>non-authoritative.</em></span>
1150 <a class="indexterm" name="id2552300"></a>
1151 At this point the browse lists appear as shown in <a href="NetworkBrowsing.html#browsubnet" title="Table 9.1. Browse Subnet Example 1">Browse Subnet Example 1</a> (these are
1152 the machines you would see in your network neighborhood if you looked in it on a particular network right now).
1154 </p><div class="table"><a name="browsubnet"></a><p class="title"><b>Table 9.1. Browse Subnet Example 1</b></p><table summary="Browse Subnet Example 1" border="1"><colgroup><col><col><col></colgroup><thead><tr><th align="left">Subnet</th><th align="left">Browse Master</th><th align="left">List</th></tr></thead><tbody><tr><td align="left">Subnet1</td><td align="left">N1_C</td><td align="left">N1_A, N1_B, N1_C, N1_D, N1_E</td></tr><tr><td align="left">Subnet2</td><td align="left">N2_B</td><td align="left">N2_A, N2_B, N2_C, N2_D</td></tr><tr><td align="left">Subnet3</td><td align="left">N3_D</td><td align="left">N3_A, N3_B, N3_C, N3_D</td></tr></tbody></table></div><p>
1156 At this point all the subnets are separate, and no machine is seen across any of the subnets.
1158 <a class="indexterm" name="id2552394"></a>
1159 <a class="indexterm" name="id2552401"></a>
1160 <a class="indexterm" name="id2552407"></a>
1161 <a class="indexterm" name="id2552414"></a>
1162 Now examine subnet 2 in <a href="NetworkBrowsing.html#brsbex" title="Table 9.2. Browse Subnet Example 2">Browse Subnet Example 2</a>.
1163 As soon as N2_B has become the LMB, it looks for a DMB with which to synchronize
1164 its browse list. It does this by querying the WINS server
1165 (N2_D) for the IP address associated with the NetBIOS name
1166 WORKGROUP<1B>. This name was registered by the DMB
1167 (N1_C) with the WINS server as soon as it was started.
1169 <a class="indexterm" name="id2552440"></a>
1170 <a class="indexterm" name="id2552447"></a>
1171 <a class="indexterm" name="id2552454"></a>
1172 <a class="indexterm" name="id2552461"></a>
1173 Once N2_B knows the address of the DMB, it
1174 tells it that is the LMB for subnet 2 by
1175 sending a <span class="emphasis"><em>MasterAnnouncement</em></span> packet as a UDP port 138 packet.
1176 It then synchronizes with it by doing a <span class="emphasis"><em>NetServerEnum2</em></span> call. This
1177 tells the DMB to send it all the server
1178 names it knows about. Once the DMB receives
1179 the <span class="emphasis"><em>MasterAnnouncement</em></span> packet, it schedules a synchronization
1180 request to the sender of that packet. After both synchronizations
1181 are complete, the browse lists look like those in <a href="NetworkBrowsing.html#brsbex" title="Table 9.2. Browse Subnet Example 2">Browse Subnet Example 2</a>
1182 </p><div class="table"><a name="brsbex"></a><p class="title"><b>Table 9.2. Browse Subnet Example 2</b></p><table summary="Browse Subnet Example 2" border="1"><colgroup><col align="left"><col align="left"><col align="justify"></colgroup><thead><tr><th align="left">Subnet</th><th align="left">Browse Master</th><th align="justify">List</th></tr></thead><tbody><tr><td align="left">Subnet1</td><td align="left">N1_C</td><td align="justify">N1_A, N1_B, N1_C, N1_D, N1_E,
1183 N2_A(*), N2_B(*), N2_C(*), N2_D(*)</td></tr><tr><td align="left">Subnet2</td><td align="left">N2_B</td><td align="justify">N2_A, N2_B, N2_C, N2_D, N1_A(*),
1184 N1_B(*), N1_C(*), N1_D(*), N1_E(*)</td></tr><tr><td align="left">Subnet3</td><td align="left">N3_D</td><td align="justify">N3_A, N3_B, N3_C, N3_D</td></tr></tbody></table></div><p>
1185 <a class="indexterm" name="id2552575"></a>
1186 Servers with an (*) after them are non-authoritative names.
1188 <a class="indexterm" name="id2552586"></a>
1189 At this point users looking in their Network Neighborhood on
1190 subnets 1 or 2 will see all the servers on both; users on
1191 subnet 3 will still see only the servers on their own subnet.
1193 <a class="indexterm" name="id2552600"></a>
1194 The same sequence of events that occurred for N2_B now occurs
1195 for the LMB on subnet 3 (N3_D). When it
1196 synchronizes browse lists with the DMB (N1_A)
1197 it gets both the server entries on subnet 1 and those on
1198 subnet 2. After N3_D has synchronized with N1_C and vica versa,
1199 the browse lists will appear as shown in <a href="NetworkBrowsing.html#brsex2" title="Table 9.3. Browse Subnet Example 3">Browse Subnet Example 3</a>
1200 </p><div class="table"><a name="brsex2"></a><p class="title"><b>Table 9.3. Browse Subnet Example 3</b></p><table summary="Browse Subnet Example 3" border="1"><colgroup><col align="left"><col align="left"><col align="justify"></colgroup><thead><tr><th align="left">Subnet</th><th align="left">Browse Master</th><th align="left">List</th></tr></thead><tbody><tr><td align="left">Subnet1</td><td align="left">N1_C</td><td align="left">N1_A, N1_B, N1_C, N1_D, N1_E,
1201 N2_A(*), N2_B(*), N2_C(*), N2_D(*), N3_A(*), N3_B(*), N3_C(*), N3_D(*)</td></tr><tr><td align="left">Subnet2</td><td align="left">N2_B</td><td align="left">N2_A, N2_B, N2_C, N2_D, N1_A(*),
1202 N1_B(*), N1_C(*), N1_D(*), N1_E(*)</td></tr><tr><td align="left">Subnet3</td><td align="left">N3_D</td><td align="left">N3_A, N3_B, N3_C, N3_D, N1_A(*),
1203 N1_B(*), N1_C(*), N1_D(*), N1_E(*), N2_A(*), N2_B(*), N2_C(*), N2_D(*)</td></tr></tbody></table></div><p>
1204 Servers with an (*) after them are non-authoritative names.
1206 At this point, users looking in their Network Neighborhood on
1207 subnets 1 or 3 will see all the servers on all subnets, while users on
1208 subnet 2 will still see only the servers on subnets 1 and 2, but not 3.
1210 <a class="indexterm" name="id2552716"></a>
1211 <a class="indexterm" name="id2552723"></a>
1212 <a class="indexterm" name="id2552730"></a>
1213 Finally, the LMB for subnet 2 (N2_B) will sync again
1214 with the DMB (N1_C) and will receive the missing
1215 server entries. Finally, as when a steady state (if no machines
1216 are removed or shut off) has been achieved, the browse lists will appear
1217 as shown in <a href="NetworkBrowsing.html#brsex3" title="Table 9.4. Browse Subnet Example 4">Browse Subnet Example 4</a>.
1218 </p><div class="table"><a name="brsex3"></a><p class="title"><b>Table 9.4. Browse Subnet Example 4</b></p><table summary="Browse Subnet Example 4" border="1"><colgroup><col align="left"><col align="left"><col align="justify"></colgroup><thead><tr><th align="left">Subnet</th><th align="left">Browse Master</th><th align="left">List</th></tr></thead><tbody><tr><td align="left">Subnet1</td><td align="left">N1_C</td><td align="left">N1_A, N1_B, N1_C, N1_D, N1_E,
1219 N2_A(*), N2_B(*), N2_C(*), N2_D(*), N3_A(*), N3_B(*),
1220 N3_C(*), N3_D(*)</td></tr><tr><td align="left">Subnet2</td><td align="left">N2_B</td><td align="left">N2_A, N2_B, N2_C, N2_D, N1_A(*),
1221 N1_B(*), N1_C(*), N1_D(*), N1_E(*), N3_A(*), N3_B(*),
1222 N3_C(*), N3_D(*)</td></tr><tr><td align="left">Subnet3</td><td align="left">N3_D</td><td align="left">N3_A, N3_B, N3_C, N3_D, N1_A(*),
1223 N1_B(*), N1_C(*), N1_D(*), N1_E(*), N2_A(*), N2_B(*),
1224 N2_C(*), N2_D(*)</td></tr></tbody></table></div><p>
1225 Servers with an (*) after them are non-authoritative names.
1227 Synchronizations between the DMB and LMBs
1228 will continue to occur, but this should remain a
1229 steady-state operation.
1231 If either router R1 or R2 fails, the following will occur:
1232 </p><div class="orderedlist"><ol type="1"><li><p>
1233 <a class="indexterm" name="id2552859"></a>
1234 Names of computers on each side of the inaccessible network fragments
1235 will be maintained for as long as 36 minutes in the Network Neighborhood
1238 Attempts to connect to these inaccessible computers will fail, but the
1239 names will not be removed from the Network Neighborhood lists.
1241 <a class="indexterm" name="id2552884"></a>
1242 <a class="indexterm" name="id2552891"></a>
1243 <a class="indexterm" name="id2552898"></a>
1244 If one of the fragments is cut off from the WINS server, it will only
1245 be able to access servers on its local subnet using subnet-isolated
1246 broadcast NetBIOS name resolution. The effect is similar to that of
1247 losing access to a DNS server.
1248 </p></li></ol></div></div></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2552915"></a>Common Errors</h2></div></div></div><p>
1249 <a class="indexterm" name="id2552923"></a>
1250 <a class="indexterm" name="id2552930"></a>
1251 Many questions are asked on the mailing lists regarding browsing. The majority of browsing
1252 problems originate from incorrect configuration of NetBIOS name resolution. Some are of
1254 </p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2552942"></a>Flushing the Samba NetBIOS Name Cache</h3></div></div></div><p>
1255 How Can One Flush the Samba NetBIOS Name Cache without Restarting Samba?
1257 <a class="indexterm" name="id2552954"></a>
1258 <a class="indexterm" name="id2552961"></a>
1259 <a class="indexterm" name="id2552968"></a>
1260 <a class="indexterm" name="id2552975"></a>
1261 Samba's <span><strong class="command">nmbd</strong></span> process controls all browse list handling. Under normal circumstances it is
1262 safe to restart <span><strong class="command">nmbd</strong></span>. This will effectively flush the Samba NetBIOS name cache and cause it
1263 to be rebuilt. This does not make certain that a rogue machine name will not reappear
1264 in the browse list. When <span><strong class="command">nmbd</strong></span> is taken out of service, another machine on the network will
1265 become the browse master. This new list may still have the rogue entry in it. If you really
1266 want to clear a rogue machine from the list, every machine on the network must be
1267 shut down and restarted after all machines are down. Failing a complete restart, the only
1268 other thing you can do is wait until the entry times out and is then flushed from the list.
1269 This may take a long time on some networks (perhaps months).
1270 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2553015"></a>Server Resources Cannot Be Listed</h3></div></div></div><p>“<span class="quote">My Client Reports "‘<span class="quote">This server is not configured to list shared resources."</span>’</span>”</p><p>
1271 Your guest account is probably invalid for some reason. Samba uses the
1272 guest account for browsing in <span><strong class="command">smbd</strong></span>. Check that your guest account is
1274 </p><p>Also see <a class="indexterm" name="id2553043"></a>guest account in the <code class="filename">smb.conf</code> man page.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2553059"></a>I Get an "<span class="errorname">Unable to browse the network</span>" Error</h3></div></div></div><p>This error can have multiple causes:
1275 <a class="indexterm" name="id2553071"></a>
1276 </p><div class="itemizedlist"><ul type="disc"><li><p>There is no LMB. Configure <span class="application">nmbd</span>
1277 or any other machine to serve as LMB.</p></li><li><p>You cannot log onto the machine that is the LMB.
1278 Can you log on to it as a guest user? </p></li><li><p>There is no IP connectivity to the LMB.
1279 Can you reach it by broadcast?</p></li></ul></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2553106"></a>Browsing of Shares and Directories is Very Slow</h3></div></div></div><p>“<span class="quote">
1280 <a class="indexterm" name="id2553116"></a>
1281 There are only two machines on a test network. One is a Samba server, the other a Windows XP machine.
1282 Authentication and logons work perfectly, but when I try to explore shares on the Samba server, the
1283 Windows XP client becomes unresponsive. Sometimes it does not respond for some minutes. Eventually,
1284 Windows Explorer will respond and displays files and directories without problem.
1286 </p><p>“<span class="quote">
1287 <a class="indexterm" name="id2553135"></a>
1288 But, the share is immediately available from a command shell (<span><strong class="command">cmd</strong></span>, followed by
1289 exploration with DOS command. Is this a Samba problem, or is it a Windows problem? How can I solve this?
1290 </span>”</p><p>
1291 Here are a few possibilities:
1292 </p><div class="variablelist"><dl><dt><span class="term">Bad Networking Hardware</span></dt><dd><p>
1293 <a class="indexterm" name="id2553166"></a>
1294 <a class="indexterm" name="id2553173"></a>
1295 <a class="indexterm" name="id2553180"></a>
1296 <a class="indexterm" name="id2553187"></a>
1297 <a class="indexterm" name="id2553194"></a>
1298 Most common defective hardware problems center around low cost or defective hubs, routers,
1299 network interface controllers (NICs), and bad wiring. If one piece of hardware is defective,
1300 the whole network may suffer. Bad networking hardware can cause data corruption. Most bad
1301 networking hardware problems are accompanied by an increase in apparent network traffic,
1303 </p></dd><dt><span class="term">The Windows XP WebClient</span></dt><dd><p>
1304 <a class="indexterm" name="id2553219"></a>
1305 A number of sites have reported similar slow network browsing problems and found that when
1306 the WebClient service is turned off, the problem disappears. This is certainly something
1307 that should be explored because it is a simple solution if it works.
1308 </p></dd><dt><span class="term">Inconsistent WINS Configuration</span></dt><dd><p>
1309 <a class="indexterm" name="id2553245"></a>
1310 <a class="indexterm" name="id2553251"></a>
1311 This type of problem is common when one client is configured to use a WINS server (that is
1312 a TCP/IP configuration setting) and there is no WINS server on the network. Alternatively,
1313 this will happen if there is a WINS server and Samba is not configured to use it. The use of
1314 WINS is highly recommended if the network is using NetBIOS over TCP/IP protocols. If use
1315 of NetBIOS over TCP/IP is disabled on all clients, Samba should not be configured as a WINS
1316 server, nor should it be configured to use one.
1317 </p></dd><dt><span class="term">Incorrect DNS Configuration</span></dt><dd><p>
1318 <a class="indexterm" name="id2553278"></a>
1319 <a class="indexterm" name="id2553285"></a>
1320 If use of NetBIOS over TCP/IP is disabled, Active Directory is in use and the DNS server
1321 has been incorrectly configured. For further information refer to
1322 <a href="NetworkBrowsing.html#adsdnstech" title="DNS and Active Directory">DNS and Active Directory</a>.
1323 </p></dd></dl></div></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="optional.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="optional.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="passdb.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Part III. Advanced Configuration </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 10. Account Information Databases</td></tr></table></div></body></html>
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