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<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter 10. Network Browsing</title><link rel="stylesheet" href="samba.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.71.0"><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="ChangeNotes.html" title="Chapter 9. Important Samba-3.0.23 Change Notes"><link rel="next" href="passdb.html" title="Chapter 11. 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 10. Network Browsing</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ChangeNotes.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 10. 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><div class="author"><h3 class="author"><span class="firstname">Jonathan</span> <span class="surname">Johnson</span></h3><div class="affiliation"><span class="orgname">Sutinen Consulting, Inc.<br></span><div class="address"><p><code class="email"><<a href="mailto:jon@sutinen.com">jon@sutinen.com</a>></code></p></div></div></div></div><div><p class="pubdate">July 5, 1998</p></div><div><p class="pubdate">Updated: September 20, 2006</p></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="NetworkBrowsing.html#id344472">Features and Benefits</a></span></dt><dt><span class="sect1"><a href="NetworkBrowsing.html#id344637">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#id345004">NetBIOS over TCP/IP</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id345560">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#id346062">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#id346923">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#id347456">Making Samba the Domain Master</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id347666">Note about Broadcast Addresses</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id347685">Multiple Interfaces</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id347854">Use of the Remote Announce Parameter</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id347978">Use of the Remote Browse Sync Parameter</a></span></dt></dl></dd><dt><span class="sect1"><a href="NetworkBrowsing.html#id348064">WINS: The Windows Internetworking Name Server</a></span></dt><dd><dl><dt><span class="sect2"><a href="NetworkBrowsing.html#id348298">WINS Server Configuration</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id348577">WINS Replication</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id348627">Static WINS Entries</a></span></dt></dl></dd><dt><span class="sect1"><a href="NetworkBrowsing.html#id348844">Helpful Hints</a></span></dt><dd><dl><dt><span class="sect2"><a href="NetworkBrowsing.html#id348854">Windows Networking Protocols</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id348980">Name Resolution Order</a></span></dt></dl></dd><dt><span class="sect1"><a href="NetworkBrowsing.html#id349177">Technical Overview of Browsing</a></span></dt><dd><dl><dt><span class="sect2"><a href="NetworkBrowsing.html#id349249">Browsing Support in Samba</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id349424">Problem Resolution</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id349647">Cross-Subnet Browsing</a></span></dt></dl></dd><dt><span class="sect1"><a href="NetworkBrowsing.html#id350588">Common Errors</a></span></dt><dd><dl><dt><span class="sect2"><a href="NetworkBrowsing.html#id350612">Flushing the Samba NetBIOS Name Cache</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id350677">Server Resources Cannot Be Listed</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id350718">I Get an "<span class="errorname">Unable to browse the network</span>" Error</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id350764">Browsing of Shares and Directories is Very Slow</a></span></dt><dt><span class="sect2"><a href="NetworkBrowsing.html#id350945">Invalid Cached Share References Affects Network Browsing</a></span></dt></dl></dd></dl></div><p>
<a class="indexterm" name="id344390"></a>
<a class="indexterm" name="id344397"></a>
<a class="indexterm" name="id344404"></a>
<a class="indexterm" name="id344411"></a>
This chapter contains detailed information as well as a fast-track guide to
implementing browsing across subnets and/or across workgroups (or domains).
WINS is the best tool for resolution of NetBIOS names to IP addresses; however, WINS is
not involved in browse list handling except by way of name-to-address resolution.
</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
<a class="indexterm" name="id344425"></a>
What is WINS?
</p><p>
WINS is a facility that provides resolution of a NetBIOS name to its IP address. WINS is like a
Dynamic-DNS service for NetBIOS networking names.
</p></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
<a class="indexterm" name="id344441"></a>
<a class="indexterm" name="id344448"></a>
<a class="indexterm" name="id344454"></a>
<a class="indexterm" name="id344461"></a>
MS Windows 2000 and later versions can be configured to operate with no NetBIOS
over TCP/IP. Samba-3 and later versions also support this mode of operation.
When the use of NetBIOS over TCP/IP has been disabled, the primary
means for resolution of MS Windows machine names is via DNS and Active Directory.
The following information assumes that your site is running NetBIOS over TCP/IP.
</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id344472"></a>Features and Benefits</h2></div></div></div><p>
Charles Dickens once referred to the past in these words: “<span class="quote"><span class="emphasis"><em>It was the best of times,
it was the worst of times.</em></span></span>” The more we look back, the more we long for what was and
hope it never returns.
</p><p>
<a class="indexterm" name="id344489"></a>
<a class="indexterm" name="id344496"></a>
<a class="indexterm" name="id344503"></a>
For many MS Windows network administrators, that statement sums up their feelings about
NetBIOS networking precisely. For those who mastered NetBIOS networking, its fickle
nature was just par for the course. For those who never quite managed to tame its
lusty features, NetBIOS is like Paterson's Curse.
</p><p>
For those not familiar with botanical problems in Australia, Paterson's Curse,
<span class="emphasis"><em>Echium plantagineum</em></span>, was introduced to Australia from Europe during the mid-19th
century. Since then it has spread rapidly. The high seed production, with densities of
thousands of seeds per square meter, a seed longevity of more than 7 years, and an
ability to germinate at any time of year, given the right conditions, are some of the
features that make it such a persistent weed.
</p><p>
<a class="indexterm" name="id344526"></a>
<a class="indexterm" name="id344535"></a>
<a class="indexterm" name="id344542"></a>
<a class="indexterm" name="id344549"></a>
<a class="indexterm" name="id344555"></a>
In this chapter we explore vital aspects of Server Message Block (SMB) networking with
a particular focus on SMB as implemented through running NetBIOS (Network Basic
Input/Output System) over TCP/IP. Since Samba does not implement SMB or NetBIOS over
any other protocols, we need to know how to configure our network environment and simply
remember to use nothing but TCP/IP on all our MS Windows network clients.
</p><p>
<a class="indexterm" name="id344569"></a>
<a class="indexterm" name="id344576"></a>
Samba provides the ability to implement a WINS (Windows Internetworking Name Server)
and implements extensions to Microsoft's implementation of WINS. These extensions
help Samba to effect stable WINS operations beyond the normal scope of MS WINS.
</p><p>
<a class="indexterm" name="id344588"></a>
<a class="indexterm" name="id344595"></a>
<a class="indexterm" name="id344602"></a>
WINS is exclusively a service that applies only to those systems
that run NetBIOS over TCP/IP. MS Windows 200x/XP have the capacity to operate with
support for NetBIOS disabled, in which case WINS is of no relevance. Samba supports this also.
</p><p>
<a class="indexterm" name="id344614"></a>
<a class="indexterm" name="id344621"></a>
<a class="indexterm" name="id344627"></a>
For those networks on which NetBIOS has been disabled (i.e., WINS is not required),
the use of DNS is necessary for hostname resolution.
</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id344637"></a>What Is Browsing?</h2></div></div></div><p>
<a class="indexterm" name="id344645"></a>
<a class="indexterm" name="id344652"></a>
<a class="indexterm" name="id344659"></a>
<a class="indexterm" name="id344666"></a>
To most people, browsing means they can see the MS Windows and Samba servers
in the Network Neighborhood, and when the computer icon for a particular server is
clicked, it opens up and shows the shares and printers available on the target server.
</p><p>
What seems so simple is in fact a complex interaction of different technologies.
The technologies (or methods) employed in making all of this work include:
</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>
<a class="indexterm" name="id344716"></a>
<a class="indexterm" name="id344722"></a>
<a class="indexterm" name="id344729"></a>
The Samba application that controls browse list management and name resolution is
called <code class="filename">nmbd</code>. The configuration parameters involved in nmbd's operation are:
</p><p>
Browsing options:
</p><div class="itemizedlist"><ul type="disc"><li><a class="indexterm" name="id344751"></a>os level</li><li><a class="indexterm" name="id344760"></a>lm announce</li><li><a class="indexterm" name="id344769"></a>lm interval</li><li><a class="indexterm" name="id344779"></a>preferred master(*)</li><li><a class="indexterm" name="id344788"></a>local master(*)</li><li><a class="indexterm" name="id344797"></a>domain master(*)</li><li><a class="indexterm" name="id344806"></a>browse list</li><li><a class="indexterm" name="id344815"></a>enhanced browsing</li></ul></div><p>
Name Resolution Method:
</p><div class="itemizedlist"><ul type="disc"><li><a class="indexterm" name="id344831"></a>name resolve order(*)</li></ul></div><p>
WINS options:
</p><div class="itemizedlist"><ul type="disc"><li><a class="indexterm" name="id344847"></a>dns proxy</li><li><a class="indexterm" name="id344856"></a>wins proxy</li><li><a class="indexterm" name="id344866"></a>wins server(*)</li><li><a class="indexterm" name="id344875"></a>wins support(*)</li><li><a class="indexterm" name="id344884"></a>wins hook</li></ul></div><p>
Those marked with an (*) are the only options that commonly may need to be modified. Even if none of these
parameters is set, <code class="filename">nmbd</code> will still do its job.
</p><p>
<a class="indexterm" name="id344906"></a>
<a class="indexterm" name="id344913"></a>
<a class="indexterm" name="id344920"></a>
<a class="indexterm" name="id344926"></a>
<a class="indexterm" name="id344933"></a>
For Samba, the WINS Server and WINS Support are mutually exclusive options. When <code class="literal">nmbd</code> is
started it will fail to execute if both options are set in the <code class="filename">smb.conf</code> file. The <code class="literal">nmbd</code>
understands that when it spawns an instance of itself to run as a WINS server that it has to use its own WINS
server also.
</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>
<a class="indexterm" name="id344973"></a>
<a class="indexterm" name="id344980"></a>
<a class="indexterm" name="id344987"></a>
<a class="indexterm" name="id344994"></a>
All MS Windows networking uses SMB-based messaging. SMB messaging may be implemented with or without NetBIOS.
MS Windows 200x supports NetBIOS over TCP/IP for backwards compatibility. Microsoft appears intent on phasing
out NetBIOS support.
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id345004"></a>NetBIOS over TCP/IP</h3></div></div></div><p>
<a class="indexterm" name="id345011"></a>
<a class="indexterm" name="id345018"></a>
<a class="indexterm" name="id345025"></a>
<a class="indexterm" name="id345032"></a>
Samba implements NetBIOS, as does MS Windows NT/200x/XP, by encapsulating it over TCP/IP.
NetBIOS-based networking uses broadcast messaging to effect browse list management. When running NetBIOS over
TCP/IP, this uses UDP-based messaging. UDP messages can be broadcast or unicast.
</p><p>
<a class="indexterm" name="id345044"></a>
Normally, only unicast UDP messaging can be forwarded by routers. The
<a class="indexterm" name="id345051"></a>remote announce parameter to smb.conf helps to project browse announcements
to remote network segments via unicast UDP. Similarly, the
<a class="indexterm" name="id345059"></a>remote browse sync parameter of <code class="filename">smb.conf</code>
implements browse list collation using unicast UDP.
</p><p>
The methods used by MS Windows to perform name lookup requests (name resolution) is determined by a
configuration parameter called the NetBIOS node-type. There are four basic NetBIOS node types:
</p><a class="indexterm" name="id345079"></a><a class="indexterm" name="id345086"></a><a class="indexterm" name="id345092"></a><a class="indexterm" name="id345099"></a><a class="indexterm" name="id345106"></a><a class="indexterm" name="id345113"></a><a class="indexterm" name="id345120"></a><a class="indexterm" name="id345126"></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
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
(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
NetBIOS broadcast requests using UDP broadcast, then it will use (NetBIOS unicast)
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
(NetBIOS unicast) requests using UDP unicast directed to a WINS server, then it will use
NetBIOS broadcast requests using UDP broadcast.</p></li></ul></div><p>
<a class="indexterm" name="id345170"></a>
<a class="indexterm" name="id345177"></a>
<a class="indexterm" name="id345184"></a>
<a class="indexterm" name="id345191"></a>
<a class="indexterm" name="id345198"></a>
<a class="indexterm" name="id345204"></a>
The default Windows network client (or server) network configuration enables NetBIOS over TCP/IP
and b-node configuration. The use of WINS makes most sense with h-node (hybrid mode) operation so that
in the event of a WINS breakdown or non-availability, the client can use broadcast-based name resolution.
</p><p>
<a class="indexterm" name="id345217"></a>
<a class="indexterm" name="id345226"></a>
<a class="indexterm" name="id345233"></a>
<a class="indexterm" name="id345239"></a>
<a class="indexterm" name="id345246"></a>
<a class="indexterm" name="id345253"></a>
<a class="indexterm" name="id345260"></a>
In those networks where Samba is the only SMB server technology, wherever possible <code class="filename">nmbd</code>
should be configured on one machine as the WINS server. This makes it easy to manage the browsing environment.
If each network segment is configured with its own Samba WINS server, then the only way to get cross-segment
browsing to work is by using the <a class="indexterm" name="id345275"></a>remote announce and the <a class="indexterm" name="id345282"></a>remote browse sync parameters to your <code class="filename">smb.conf</code> file.
</p><p>
<a class="indexterm" name="id345299"></a>
If only one WINS server is used for an entire multisegment network, then
the use of the <a class="indexterm" name="id345307"></a>remote announce and the
<a class="indexterm" name="id345314"></a>remote browse sync parameters should not be necessary.
</p><p>
<a class="indexterm" name="id345324"></a>
As of Samba-3, WINS replication is being worked on. The bulk of the code has been committed, but it still
needs maturation. This is not a supported feature of the Samba-3.0.20 release. Hopefully, this will become a
supported feature of one of the Samba-3 release series. The delay is caused by the fact that this feature has
not been of sufficient significance to inspire someone to pay a developer to complete it.
</p><p>
<a class="indexterm" name="id345340"></a>
<a class="indexterm" name="id345347"></a>
<a class="indexterm" name="id345354"></a>
<a class="indexterm" name="id345361"></a>
<a class="indexterm" name="id345367"></a>
<a class="indexterm" name="id345374"></a>
<a class="indexterm" name="id345381"></a>
<a class="indexterm" name="id345388"></a>
Right now Samba WINS does not support MS-WINS replication. This means that when setting up Samba as a WINS
server, there must only be one <code class="filename">nmbd</code> configured as a WINS server on the network. Some
sites have used multiple Samba WINS servers for redundancy (one server per subnet) and then used
<a class="indexterm" name="id345403"></a>remote browse sync and <a class="indexterm" name="id345410"></a>remote announce to effect browse list
collation across all segments. Note that this means clients will only resolve local names and must be
configured to use DNS to resolve names on other subnets in order to resolve the IP addresses of the servers
they can see on other subnets. This setup is not recommended but is mentioned as a practical consideration
(i.e., an “<span class="quote">if all else fails</span>” scenario). NetBIOS over TCP/IP is an ugly and difficult to manage
protocol. Its replacement, NetBIOSless SMB over TCP/IP is not without its own manageability concerns. NetBIOS
based networking is a life of compromise and trade-offs. WINS stores information that cannot be stored in
DNS; consequently, DNS is a poor substitute for WINS given that when NetBIOS over TCP/IP is used, Windows
clients are designed to use WINS.
</p><p>
<a class="indexterm" name="id345430"></a>
<a class="indexterm" name="id345437"></a>
<a class="indexterm" name="id345444"></a>
Lastly, take note that browse lists are a collection of unreliable broadcast
messages that are repeated at intervals of not more than 15 minutes. This means
that it will take time to establish a browse list, and it can take up to 45
minutes to stabilize, particularly across network segments.
</p><p>
<a class="indexterm" name="id345456"></a>
When an MS Windows 200x/XP system attempts to resolve a host name to an IP address, it follows a defined path:
</p><div class="orderedlist"><ol type="1"><li><p>
Checks the <code class="filename">hosts</code> file. It is located in <code class="filename">%SystemRoot%\System32\Drivers\etc</code>.
</p></li><li><p>
Does a DNS lookup.
</p></li><li><p>
Checks the NetBIOS name cache.
</p></li><li><p>
Queries the WINS server.
</p></li><li><p>
Does a broadcast name lookup over UDP.
</p></li><li><p>
Looks up entries in LMHOSTS, located in <code class="filename">%SystemRoot%\System32\Drivers\etc</code>.
</p></li></ol></div><p>
<a class="indexterm" name="id345521"></a>
<a class="indexterm" name="id345528"></a>
<a class="indexterm" name="id345535"></a>
<a class="indexterm" name="id345542"></a>
Given the nature of how the NetBIOS over TCP/IP protocol is implemented, only WINS is capable of resolving
with any reliability name lookups for service-oriented names such as TEMPTATION<1C> a NetBIOS
name query that seeks to find network logon servers. DNS has no concept of service-oriented names such as
this. In fact, the Microsoft ADS implementation specifically manages a whole range of extended
service-oriented DNS entries. This type of facility is not implemented and is not supported for the NetBIOS
over TCP/IP protocol namespace.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id345560"></a>TCP/IP without NetBIOS</h3></div></div></div><p>
<a class="indexterm" name="id345567"></a>
<a class="indexterm" name="id345574"></a>
<a class="indexterm" name="id345580"></a>
All TCP/IP-enabled systems use various forms of hostname resolution. The primary
methods for TCP/IP hostname resolution involve either a static file (<code class="filename">/etc/hosts</code>)
or the Domain Name System (DNS). DNS is the technology that makes
the Internet usable. DNS-based hostname resolution is supported by nearly all
TCP/IP-enabled systems. Only a few embedded TCP/IP systems do not support DNS.
</p><p>
<a class="indexterm" name="id345599"></a>
<a class="indexterm" name="id345606"></a>
<a class="indexterm" name="id345613"></a>
<a class="indexterm" name="id345619"></a>
Windows 200x/XP can register its hostname with a Dynamic DNS server (DDNS). It is possible to force register with a
dynamic DNS server in Windows 200x/XP using <code class="literal">ipconfig /registerdns</code>.
</p><p>
<a class="indexterm" name="id345639"></a>
<a class="indexterm" name="id345646"></a>
<a class="indexterm" name="id345652"></a>
With Active Directory, a correctly functioning DNS server is absolutely essential. In the absence of a working
DNS server that has been correctly configured, MS Windows clients and servers will be unable to locate each
other, so network services consequently will be severely impaired.
</p><p>
<a class="indexterm" name="id345665"></a>
<a class="indexterm" name="id345671"></a>
<a class="indexterm" name="id345678"></a>
<a class="indexterm" name="id345685"></a>
<a class="indexterm" name="id345692"></a>
<a class="indexterm" name="id345698"></a>
Use of raw SMB over TCP/IP (No NetBIOS layer) can be done only with Active Directory domains. Samba is not an
Active Directory domain controller: ergo, it is not possible to run Samba as a domain controller and at the same
time <span class="emphasis"><em>not</em></span> use NetBIOS. Where Samba is used as an Active Directory domain member server
(DMS) it is possible to configure Samba to not use NetBIOS over TCP/IP. A Samba DMS can integrate fully into
an Active Directory domain, however, if NetBIOS over TCP/IP is disabled, it is necessary to manually create
appropriate DNS entries for the Samba DMS because they will not be automatically generated either by Samba, or
by the ADS environment.
</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>
<a class="indexterm" name="id345728"></a>
<a class="indexterm" name="id345736"></a>
<a class="indexterm" name="id345743"></a>
<a class="indexterm" name="id345750"></a>
<a class="indexterm" name="id345756"></a>
Occasionally we hear from UNIX network administrators who want to use a UNIX-based DDNS server in place
of the Microsoft DNS server. While this might be desirable to some, the MS Windows 200x DNS server is
autoconfigured to work with Active Directory. It is possible to use BIND version 8 or 9, but it will almost
certainly be necessary to create service records (SRV records) so MS Active Directory clients can resolve
hostnames to locate essential network services. The following are some of the default service records that
Active Directory requires:
</p><p>
<a class="indexterm" name="id345773"></a>
<a class="indexterm" name="id345780"></a>
<a class="indexterm" name="id345787"></a>
The use of DDNS is highly recommended with Active Directory, in which case the use of BIND9 is preferred for
its ability to adequately support the SRV (service) records that are needed for Active Directory. Of course,
when running ADS, it makes sense to use Microsoft's own DDNS server because of the natural affinity between ADS
and MS DNS.
</p><div class="variablelist"><dl><dt><span class="term">_ldap._tcp.pdc._msdcs.<span class="emphasis"><em>Domain</em></span></span></dt><dd><p>
This provides the address of the Windows NT PDC for the domain.
</p></dd><dt><span class="term">_ldap._tcp.pdc._msdcs.<span class="emphasis"><em>DomainTree</em></span></span></dt><dd><p>
Resolves the addresses of global catalog servers in the domain.
</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>
Provides list of domain controllers based on sites.
</p></dd><dt><span class="term">_ldap._tcp.writable._msdcs.<span class="emphasis"><em>Domain</em></span></span></dt><dd><p>
Enumerates list of domain controllers that have the writable copies of the Active Directory data store.
</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>
Entry used by MS Windows clients to locate machines using the global unique identifier.
</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>
Used by Microsoft Windows clients to locate the site configuration-dependent global catalog server.
</p></dd></dl></div><p>
Specific entries used by Microsoft clients to locate essential services for an example domain
called <code class="constant">quenya.org</code> include:
</p><div class="itemizedlist"><ul type="disc"><li><p>
_kerberos._udp.quenya.org Used to contact the KDC server via UDP.
This entry must list port 88 for each KDC.
</p></li><li><p>
_kpasswd._udp.quenya.org Used to locate the <code class="constant">kpasswd</code> server
when a user password change must be processed. This record must list port 464 on the
master KDC.
</p></li><li><p>
_kerberos._tcp.quenya.org Used to locate the KDC server via TCP.
This entry must list port 88 for each KDC.
</p></li><li><p>
_ldap._tcp.quenya.org Used to locate the LDAP service on the PDC.
This record must list port 389 for the PDC.
</p></li><li><p>
_kpasswd._tcp.quenya.org Used to locate the <code class="constant">kpasswd</code> server
to permit user password changes to be processed. This must list port 464.
</p></li><li><p>
_gc._tcp.quenya.org Used to locate the global catalog server for the
top of the domain. This must list port 3268.
</p></li></ul></div><p>
The following records are also used by the Windows domain member client to locate vital
services on the Windows ADS domain controllers.
</p><div class="itemizedlist"><ul type="disc"><li><p>
_ldap._tcp.pdc._msdcs.quenya.org
</p></li><li><p>
_ldap.gc._msdcs.quenya.org
</p></li><li><p>
_ldap.default-first-site-name._sites.gc._msdcs.quenya.org
</p></li><li><p>
_ldap.{SecID}.domains._msdcs.quenya.org
</p></li><li><p>
_ldap._tcp.dc._msdcs.quenya.org
</p></li><li><p>
_kerberos._tcp.dc._msdcs.quenya.org
</p></li><li><p>
_ldap.default-first-site-name._sites.dc._msdcs.quenya.org
</p></li><li><p>
_kerberos.default-first-site-name._sites.dc._msdcs.queyna.org
</p></li><li><p>
SecID._msdcs.quenya.org
</p></li></ul></div><p>
Presence of the correct DNS entries can be validated by executing:
</p><pre class="screen">
<code class="prompt">root# </code> dig @frodo -t any _ldap._tcp.dc._msdcs.quenya.org
; <lt;>> DiG 9.2.2 <lt;>> @frodo -t any _ldap._tcp.dc._msdcs.quenya.org
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3072
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 2
;; QUESTION SECTION:
;_ldap._tcp.dc._msdcs.quenya.org. IN ANY
;; ANSWER SECTION:
_ldap._tcp.dc._msdcs.quenya.org. 600 IN SRV 0 100 389 frodo.quenya.org.
_ldap._tcp.dc._msdcs.quenya.org. 600 IN SRV 0 100 389 noldor.quenya.org.
;; ADDITIONAL SECTION:
frodo.quenya.org. 3600 IN A 10.1.1.16
noldor.quenya.org. 1200 IN A 10.1.1.17
;; Query time: 0 msec
;; SERVER: frodo#53(10.1.1.16)
;; WHEN: Wed Oct 7 14:39:31 2004
;; MSG SIZE rcvd: 171
</pre><p>
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id346062"></a>How Browsing Functions</h2></div></div></div><p>
<a class="indexterm" name="id346069"></a>
<a class="indexterm" name="id346076"></a>
<a class="indexterm" name="id346083"></a>
<a class="indexterm" name="id346089"></a>
<a class="indexterm" name="id346096"></a>
MS Windows machines register their NetBIOS names (i.e., the machine name for each service type in operation)
on startup. The exact method by which this name registration takes place is determined by whether or not the
MS Windows client/server has been given a WINS server address, whether or not LMHOSTS lookup is enabled,
whether or not DNS for NetBIOS name resolution is enabled, and so on.
</p><p>
<a class="indexterm" name="id346110"></a>
<a class="indexterm" name="id346116"></a>
<a class="indexterm" name="id346123"></a>
In the case where there is no WINS server, all name registrations as well as name lookups are done by UDP
broadcast. This isolates name resolution to the local subnet, unless LMHOSTS is used to list all names and IP
addresses. In such situations, Samba provides a means by which the Samba server name may be forcibly injected
into the browse list of a remote MS Windows network (using the <a class="indexterm" name="id346133"></a>remote announce
parameter).
</p><p>
<a class="indexterm" name="id346144"></a>
<a class="indexterm" name="id346150"></a>
<a class="indexterm" name="id346157"></a>
Where a WINS server is used, the MS Windows client will use UDP unicast to register with the WINS server. Such
packets can be routed, and thus WINS allows name resolution to function across routed networks.
</p><p>
<a class="indexterm" name="id346169"></a>
<a class="indexterm" name="id346176"></a>
<a class="indexterm" name="id346185"></a>
<a class="indexterm" name="id346191"></a>
<a class="indexterm" name="id346198"></a>
<a class="indexterm" name="id346205"></a>
<a class="indexterm" name="id346212"></a>
<a class="indexterm" name="id346218"></a>
During the startup process, an election takes place to create a local master browser (LMB) if one does not
already exist. On each NetBIOS network one machine will be elected to function as the domain master browser
(DMB). This domain browsing has nothing to do with MS security Domain Control. Instead, the DMB serves the
role of contacting each LMB (found by asking WINS or from LMHOSTS) and exchanging browse list contents. This
way every master browser will eventually obtain a complete list of all machines that are on the network. Every
11 to 15 minutes an election is held to determine which machine will be the master browser. By the nature of
the election criteria used, the machine with the highest uptime, or the most senior protocol version or other
criteria, will win the election as DMB.
</p><p>
<a class="indexterm" name="id346235"></a>
<a class="indexterm" name="id346242"></a>
<a class="indexterm" name="id346248"></a>
<a class="indexterm" name="id346255"></a>
<a class="indexterm" name="id346262"></a>
<a class="indexterm" name="id346269"></a>
<a class="indexterm" name="id346276"></a>
<a class="indexterm" name="id346282"></a>
Where a WINS server is used, the DMB registers its IP address with the WINS server using the name of the
domain and the NetBIOS name type 1B (e.g., DOMAIN<1B>). All LMBs register their IP addresses with the WINS
server, also with the name of the domain and the NetBIOS name type of 1D. The 1B name is unique to one
server within the domain security context, and only one 1D name is registered for each network segment.
Machines that have registered the 1D name will be authoritive browse list maintainers for the network segment
they are on. The DMB is responsible for synchronizing the browse lists it obtains from the LMBs.
</p><p>
<a class="indexterm" name="id346305"></a>
Clients wishing to browse the network make use of this list but also depend on the availability of correct
name resolution to the respective IP address or addresses.
</p><p>
<a class="indexterm" name="id346317"></a>
Any configuration that breaks name resolution and/or browsing intrinsics will annoy users because they will
have to put up with protracted inability to use the network services.
</p><p>
<a class="indexterm" name="id346328"></a>
<a class="indexterm" name="id346335"></a>
<a class="indexterm" name="id346342"></a>
<a class="indexterm" name="id346349"></a>
<a class="indexterm" name="id346355"></a>
<a class="indexterm" name="id346362"></a>
Samba supports a feature that allows forced synchronization of browse lists across routed networks using the
<a class="indexterm" name="id346370"></a>remote browse sync parameter in the <code class="filename">smb.conf</code> file. This causes Samba to contact the
LMB on a remote network and to request browse list synchronization. This effectively bridges two networks that
are separated by routers. The two remote networks may use either broadcast-based name resolution or WINS-based
name resolution, but it should be noted that the <a class="indexterm" name="id346385"></a>remote browse sync parameter provides
browse list synchronization and that is distinct from name-to-address resolution. In other words,
for cross-subnet browsing to function correctly, it is essential that a name-to-address resolution mechanism
be provided. This mechanism could be via DNS, <code class="filename">/etc/hosts</code>, and so on.
</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>
<a class="indexterm" name="id346415"></a>
<a class="indexterm" name="id346422"></a>
<a class="indexterm" name="id346428"></a>
<a class="indexterm" name="id346435"></a>
<a class="indexterm" name="id346441"></a>
<a class="indexterm" name="id346448"></a>
To configure cross-subnet browsing on a network containing machines in a workgroup, not an NT domain, you need
to set up one Samba server to be the DMB (note that this is not the same as a Primary Domain Controller,
although in an NT domain the same machine plays both roles). The role of a DMB is to collate the browse lists
from LMB on all the subnets that have a machine participating in the workgroup. Without one machine configured
as a DMB, each subnet would be an isolated workgroup unable to see any machines on another subnet. It is the
presence of a DMB that makes cross-subnet browsing possible for a workgroup.
</p><p>
<a class="indexterm" name="id346464"></a>
In a workgroup environment the DMB must be a Samba server, and there must only be one DMB per workgroup name.
To set up a Samba server as a DMB, set the following option in the <em class="parameter"><code>[global]</code></em> section
of the <code class="filename">smb.conf</code> file:
</p><p>
</p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id346492"></a><em class="parameter"><code>domain master = yes</code></em></td></tr></table><p>
</p><p>
<a class="indexterm" name="id346508"></a>
<a class="indexterm" name="id346515"></a>
The DMB should preferably be the LMB for its own subnet. In order to achieve this, 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#dmbexample" title="Example 10.1. Domain Master Browser smb.conf">Domain Master Browser smb.conf</a>
</p><div class="example"><a name="dmbexample"></a><p class="title"><b>Example 10.1. Domain Master Browser smb.conf</b></p><div class="example-contents"><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="id346567"></a><em class="parameter"><code>domain master = yes</code></em></td></tr><tr><td><a class="indexterm" name="id346580"></a><em class="parameter"><code>local master = yes</code></em></td></tr><tr><td><a class="indexterm" name="id346592"></a><em class="parameter"><code>preferred master = yes</code></em></td></tr><tr><td><a class="indexterm" name="id346605"></a><em class="parameter"><code>os level = 65</code></em></td></tr></table></div></div><br class="example-break"><p>
<a class="indexterm" name="id346620"></a>
<a class="indexterm" name="id346627"></a>
The DMB may be the same machine as the WINS server, if necessary.
</p><p>
<a class="indexterm" name="id346638"></a>
<a class="indexterm" name="id346644"></a>
<a class="indexterm" name="id346651"></a>
Next, you should ensure that each of the subnets contains a machine that can act as an LMB for the workgroup.
Any MS Windows NT/200x/XP machine should be able to do this, as will Windows 9x/Me machines (although these
tend to get rebooted more often, so it is not such a good idea to use them). To make a Samba server an LMB,
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#lmbexample" title="Example 10.2. Local master browser smb.conf">Local master browser smb.conf</a>
</p><div class="example"><a name="lmbexample"></a><p class="title"><b>Example 10.2. Local master browser smb.conf</b></p><div class="example-contents"><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="id346706"></a><em class="parameter"><code>domain master = no</code></em></td></tr><tr><td><a class="indexterm" name="id346718"></a><em class="parameter"><code>local master = yes</code></em></td></tr><tr><td><a class="indexterm" name="id346731"></a><em class="parameter"><code>preferred master = yes</code></em></td></tr><tr><td><a class="indexterm" name="id346744"></a><em class="parameter"><code>os level = 65</code></em></td></tr></table></div></div><br class="example-break"><p>
<a class="indexterm" name="id346759"></a>
Do not do this for more than one Samba server on each subnet, or they will war with
each other over which is to be the LMB.
</p><p>
<a class="indexterm" name="id346770"></a>
<a class="indexterm" name="id346777"></a>
The <a class="indexterm" name="id346784"></a>local master parameter allows Samba to act as a
LMB. The <a class="indexterm" name="id346791"></a>preferred master causes <code class="literal">nmbd</code>
to force a browser election on startup and the <a class="indexterm" name="id346805"></a>os level
parameter sets Samba high enough so it should win any browser elections.
</p><p>
<a class="indexterm" name="id346816"></a>
If you have an NT machine on the subnet that you wish to be the LMB, you can disable Samba from
becoming an LMB by 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 in <a href="NetworkBrowsing.html#nombexample" title="Example 10.3. smb.conf for Not Being a Master Browser">smb.conf for Not Being a Master Browser</a>.
</p><p>
</p><div class="example"><a name="nombexample"></a><p class="title"><b>Example 10.3. smb.conf for Not Being a Master Browser</b></p><div class="example-contents"><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="id346870"></a><em class="parameter"><code>domain master = no</code></em></td></tr><tr><td><a class="indexterm" name="id346882"></a><em class="parameter"><code>local master = no</code></em></td></tr><tr><td><a class="indexterm" name="id346895"></a><em class="parameter"><code>preferred master = no</code></em></td></tr><tr><td><a class="indexterm" name="id346907"></a><em class="parameter"><code>os level = 0</code></em></td></tr></table></div></div><p><br class="example-break">
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id346923"></a>Domain Browsing Configuration</h3></div></div></div><p>
<a class="indexterm" name="id346931"></a>
<a class="indexterm" name="id346937"></a>
<a class="indexterm" name="id346944"></a>
<a class="indexterm" name="id346951"></a>
If you are adding Samba servers to a Windows NT domain, then you must not set up a Samba server as a DMB. By
default, a Windows NT PDC for a domain is also the DMB for that domain. Network browsing may break if a Samba
server other than the PDC registers the DMB NetBIOS name (<em class="replaceable"><code>DOMAIN</code></em><1B>) with
WINS.
</p><p>
<a class="indexterm" name="id346967"></a>
For subnets other than the one containing the Windows NT PDC, you may set up Samba servers as LMBs as
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 10.4. Local Master Browser smb.conf">Local Master Browser
smb.conf</a>
</p><div class="example"><a name="remsmb"></a><p class="title"><b>Example 10.4. Local Master Browser smb.conf</b></p><div class="example-contents"><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="id347020"></a><em class="parameter"><code>domain master = no</code></em></td></tr><tr><td><a class="indexterm" name="id347032"></a><em class="parameter"><code>local master = yes</code></em></td></tr><tr><td><a class="indexterm" name="id347045"></a><em class="parameter"><code>preferred master = yes</code></em></td></tr><tr><td><a class="indexterm" name="id347058"></a><em class="parameter"><code>os level = 65</code></em></td></tr></table></div></div><br class="example-break"><p>
<a class="indexterm" name="id347073"></a>
<a class="indexterm" name="id347080"></a>
If you wish to have a Samba server fight the election with machines on the same subnet, you may set the
<a class="indexterm" name="id347088"></a>os level parameter to lower levels. By doing this you can tune the order of machines
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>.
</p><p>
<a class="indexterm" name="id347108"></a>
<a class="indexterm" name="id347114"></a>
<a class="indexterm" name="id347121"></a>
If you have Windows NT machines that are members of the domain on all subnets and you are sure they will
always be running, you can disable Samba from taking part in browser elections and ever becoming an LMB by
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
in <a href="NetworkBrowsing.html#xremmb" title="Example 10.5. smb.conf for Not Being a master browser"><code class="filename">smb.conf</code> for Not Being a master browser</a>
</p><p>
</p><div class="example"><a name="xremmb"></a><p class="title"><b>Example 10.5. <code class="filename">smb.conf</code> for Not Being a master browser</b></p><div class="example-contents"><em class="parameter"><code>[global]</code></em><a class="indexterm" name="id347176"></a>domain master = no
<a class="indexterm" name="id347183"></a>local master = no
<a class="indexterm" name="id347190"></a>preferred master = no
<a class="indexterm" name="id347198"></a>os level = 0
</div></div><p><br class="example-break">
</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>
<a class="indexterm" name="id347220"></a>
<a class="indexterm" name="id347226"></a>
<a class="indexterm" name="id347233"></a>
<a class="indexterm" name="id347240"></a>
<a class="indexterm" name="id347246"></a>
<a class="indexterm" name="id347253"></a>
<a class="indexterm" name="id347260"></a>
Who becomes the master browser is determined by an election process using broadcasts. Each election packet
contains a number of parameters that determine what precedence (bias) a host should have in the election. By
default Samba uses a low precedence and thus loses elections to just about every Windows network server or
client.
</p><p>
If you want Samba to win elections, set the <a class="indexterm" name="id347274"></a>os level global option in <code class="filename">smb.conf</code> to a
higher number. It defaults to 20. Using 34 would make it win all elections over every other system (except
other Samba systems).
</p><p>
An <a class="indexterm" name="id347291"></a>os level of two would make it beat Windows for Workgroups and Windows 9x/Me, but
not MS Windows NT/200x Server. An MS Windows NT/200x Server domain controller uses level 32. The maximum os
level is 255.
</p><p>
<a class="indexterm" name="id347303"></a>
<a class="indexterm" name="id347310"></a>
<a class="indexterm" name="id347317"></a>
<a class="indexterm" name="id347324"></a>
If you want Samba to force an election on startup, set the <a class="indexterm" name="id347331"></a>preferred master global
option in <code class="filename">smb.conf</code> to <code class="constant">yes</code>. Samba will then have a slight advantage over other
potential master browsers that are not preferred master browsers. Use this parameter with care, because if
you have two hosts (whether they are Windows 9x/Me or NT/200x/XP or Samba) on the same local subnet both set
with <a class="indexterm" name="id347350"></a>preferred master to <code class="constant">yes</code>, then periodically and continually
they will force an election in order to become the LMB.
</p><p>
<a class="indexterm" name="id347364"></a>
<a class="indexterm" name="id347370"></a>
<a class="indexterm" name="id347377"></a>
<a class="indexterm" name="id347384"></a>
<a class="indexterm" name="id347390"></a>
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="id347401"></a>preferred master to <code class="constant">yes</code>, because Samba will not become a DMB for the whole of
your LAN or WAN if it is not also a LMB on its own broadcast isolated subnet.
</p><p>
<a class="indexterm" name="id347416"></a>
<a class="indexterm" name="id347423"></a>
<a class="indexterm" name="id347429"></a>
<a class="indexterm" name="id347436"></a>
<a class="indexterm" name="id347443"></a>
It is possible to configure two Samba servers to attempt to become the DMB for a domain. The first server that
comes up will be the DMB. All other Samba servers will attempt to become the DMB every 5 minutes. They will
find that another Samba server is already the DMB and will fail. This provides automatic redundancy should the
current DMB fail. The network bandwidth overhead of browser elections is relatively small, requiring
approximately four UDP packets per machine per election. The maximum size of a UDP packet is 576 bytes.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id347456"></a>Making Samba the Domain Master</h3></div></div></div><p>
<a class="indexterm" name="id347464"></a>
<a class="indexterm" name="id347471"></a>
<a class="indexterm" name="id347478"></a>
<a class="indexterm" name="id347484"></a>
The domain master browser is responsible for collating the browse lists of multiple subnets so browsing can
occur between subnets. You can make Samba act as the domain master browser by setting <a class="indexterm" name="id347493"></a>domain master = yes in <code class="filename">smb.conf</code>. By default it will not be a domain master browser.
</p><p>
<a class="indexterm" name="id347509"></a>
<a class="indexterm" name="id347516"></a>
Do not set Samba to be the domain master for a workgroup that has the same name as an NT/200x domain. If
Samba is configured to be the domain master for a workgroup that is present on the same network as a Windows
NT/200x domain that has the same name, network browsing problems will certainly be experienced.
</p><p>
When Samba is the domain master and the master browser, it will listen for master announcements (made roughly
every 12 minutes) from LMBs on other subnets and then contact them to synchronize browse lists.
</p><p>
<a class="indexterm" name="id347534"></a>
<a class="indexterm" name="id347541"></a>
If you want Samba to be the domain master, you should also set the <a class="indexterm" name="id347548"></a>os level high
enough to make sure it wins elections, and set <a class="indexterm" name="id347556"></a>preferred master to
<code class="constant">yes</code>, to get Samba to force an election on startup.
</p><p>
<a class="indexterm" name="id347570"></a>
<a class="indexterm" name="id347577"></a>
All servers (including Samba) and clients should be using a WINS server to resolve NetBIOS names. If your
clients are only using broadcasting to resolve NetBIOS names, then two things will occur:
</p><div class="orderedlist"><ol type="1"><li><p>
<a class="indexterm" name="id347597"></a>
<a class="indexterm" name="id347604"></a>
LMBs will be unable to find a DMB because they will be looking only on the local subnet.
</p></li><li><p>
<a class="indexterm" name="id347618"></a>
If a client happens to get hold of a domain-wide browse list and a user attempts to access a
host in that list, it will be unable to resolve the NetBIOS name of that host.
</p></li></ol></div><p>
<a class="indexterm" name="id347631"></a>
If, however, both Samba and your clients are using a WINS server, then:
</p><div class="orderedlist"><ol type="1"><li><p>
LMBs will contact the WINS server and, as long as Samba has registered that it is a DMB with the WINS
server, the LMB will receive Samba's IP address as its DMB.
</p></li><li><p>
When a client receives a domain-wide browse list and a user attempts to access a host in that list, it will
contact the WINS server to resolve the NetBIOS name of that host. As long as that host has registered its
NetBIOS name with the same WINS server, the user will be able to see that host..
</p></li></ol></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id347666"></a>Note about Broadcast Addresses</h3></div></div></div><p>
<a class="indexterm" name="id347674"></a>
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
does not seem to support a zeros broadcast, and you will probably find that browsing and name lookups will not work.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id347685"></a>Multiple Interfaces</h3></div></div></div><p>
<a class="indexterm" name="id347693"></a>
Samba supports machines with multiple network interfaces. If you have multiple interfaces, you will
need to use the <a class="indexterm" name="id347701"></a>interfaces option in <code class="filename">smb.conf</code> to configure them. For example, the
machine you are working with has 4 network interfaces; <code class="literal">eth0</code>, <code class="literal">eth1</code>,
<code class="literal">eth2</code>, <code class="literal">eth3</code> and only interfaces <code class="literal">eth1</code> and
<code class="literal">eth4</code> should be used by Samba. In this case, the following <code class="filename">smb.conf</code> file entries would
permit that intent:
</p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id347762"></a><em class="parameter"><code>interfaces = eth1, eth4</code></em></td></tr><tr><td><a class="indexterm" name="id347774"></a><em class="parameter"><code>bind interfaces only = Yes</code></em></td></tr></table><p>
<a class="indexterm" name="id347787"></a>
<a class="indexterm" name="id347794"></a>
<a class="indexterm" name="id347800"></a>
<a class="indexterm" name="id347807"></a>
<a class="indexterm" name="id347814"></a>
<a class="indexterm" name="id347821"></a>
<a class="indexterm" name="id347827"></a>
The <a class="indexterm" name="id347834"></a>bind interfaces only = Yes is necessary to exclude TCP/IP session
services (ports 135, 139, and 445) over the interfaces that are not specified. Please be aware that
<code class="literal">nmbd</code> will listen for incoming UDP port 137 packets on the unlisted interfaces, but it will
not answer them. It will, however, send its broadcast packets over the unlisted interfaces. Total isolation of
ethernet interface requires the use of a firewall to block ports 137 and 138 (UDP), and ports 135, 139, and
445 (TCP) on all network interfaces that must not be able to access the Samba server.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id347854"></a>Use of the Remote Announce Parameter</h3></div></div></div><p>
The <a class="indexterm" name="id347862"></a>remote announce parameter of
<code class="filename">smb.conf</code> can be used to forcibly ensure
that all the NetBIOS names on a network get announced to a remote network.
The syntax of the <a class="indexterm" name="id347876"></a>remote announce parameter is:
</p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id347889"></a><em class="parameter"><code>remote announce = 192.168.12.23 [172.16.21.255] ...</code></em></td></tr></table><p>
<span class="emphasis"><em>or</em></span>
</p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id347910"></a><em class="parameter"><code>remote announce = 192.168.12.23/MIDEARTH [172.16.21.255/ELVINDORF] ...</code></em></td></tr></table><p>
where:
</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>
<a class="indexterm" name="id347938"></a>
<a class="indexterm" name="id347947"></a>
is either the LMB IP address or the broadcast address of the remote network.
That is, the LMB is at 192.168.1.23, or the address could be given as 172.16.21.255 where the netmask
is assumed to be 24 bits (255.255.255.0). When the remote announcement is made to the broadcast
address of the remote network, every host will receive our announcements. This is noisy and therefore
undesirable but may be necessary if we do not know the IP address of the remote LMB.
</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
workgroup name of the remote network, our NetBIOS machine names will end up looking like
they belong to that workgroup. This may cause name resolution problems and should be avoided.
</p></dd></dl></div><p>
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id347978"></a>Use of the Remote Browse Sync Parameter</h3></div></div></div><p>
<a class="indexterm" name="id347986"></a>
<a class="indexterm" name="id347992"></a>
The <a class="indexterm" name="id347999"></a>remote browse sync parameter of <code class="filename">smb.conf</code> is used to announce to another LMB that
it must synchronize its NetBIOS name list with our Samba LMB. This works only if the Samba server that has
this option is simultaneously the LMB on its network segment.
</p><p>
The syntax of the <a class="indexterm" name="id348017"></a>remote browse sync parameter is:
</p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id348030"></a><em class="parameter"><code>remote browse sync</code></em></td></tr></table><p>
<a class="indexterm" name="id348043"></a>
<a class="indexterm" name="id348049"></a>
where <em class="replaceable"><code>192.168.10.40</code></em> is either the IP address of the
remote LMB or the network broadcast address of the remote segment.
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id348064"></a>WINS: The Windows Internetworking Name Server</h2></div></div></div><p>
<a class="indexterm" name="id348072"></a>
<a class="indexterm" name="id348079"></a>
<a class="indexterm" name="id348085"></a>
Use of WINS (either Samba WINS or MS Windows NT Server WINS) is highly
recommended. Every NetBIOS machine registers its name together with a
name_type value for each of several types of service it has available.
It registers its name directly as a unique (the type 0x03) name.
It also registers its name if it is running the LanManager-compatible
server service (used to make shares and printers available to other users)
by registering the server (the type 0x20) name.
</p><p>
<a class="indexterm" name="id348099"></a>
<a class="indexterm" name="id348106"></a>
All NetBIOS names are up to 15 characters in length. The name_type variable
is added to the end of the name, thus creating a 16 character name. Any
name that is shorter than 15 characters is padded with spaces to the 15th
character. Thus, all NetBIOS names are 16 characters long (including the
name_type information).
</p><p>
<a class="indexterm" name="id348119"></a>
<a class="indexterm" name="id348126"></a>
<a class="indexterm" name="id348133"></a>
<a class="indexterm" name="id348139"></a>
WINS can store these 16-character names as they get registered. A client
that wants to log onto the network can ask the WINS server for a list
of all names that have registered the NetLogon service name_type. This saves
broadcast traffic and greatly expedites logon processing. Since broadcast
name resolution cannot be used across network segments, this type of
information can only be provided via WINS or via a statically configured
<code class="filename">lmhosts</code> file that must reside on all clients in the
absence of WINS.
</p><p>
<a class="indexterm" name="id348160"></a>
<a class="indexterm" name="id348166"></a>
<a class="indexterm" name="id348173"></a>
<a class="indexterm" name="id348179"></a>
<a class="indexterm" name="id348186"></a>
WINS also forces browse list synchronization by all LMBs. LMBs must synchronize their browse list with the
DMB, and WINS helps the LMB to identify its DMB. By definition this will work only within a single workgroup.
Note that the DMB has nothing to do with what is referred to as an MS Windows NT domain. The latter is a
reference to a security environment, while the DMB refers to the master controller for browse list information
only.
</p><p>
<a class="indexterm" name="id348200"></a>
<a class="indexterm" name="id348207"></a>
<a class="indexterm" name="id348214"></a>
<a class="indexterm" name="id348220"></a>
WINS will work correctly only if every client TCP/IP protocol stack
is configured to use the WINS servers. Any client that is not
configured to use the WINS server will continue to use only broadcast-based
name registration, so WINS may never get to know about it. In any case,
machines that have not registered with a WINS server will fail name-to-address
lookup attempts by other clients and will therefore cause workstation access
errors.
</p><p>
To configure Samba as a WINS server, just add
<a class="indexterm" name="id348235"></a>wins support = yes to the <code class="filename">smb.conf</code>
file [global] section.
</p><p>
To configure Samba to register with a WINS server, just add <a class="indexterm" name="id348252"></a>wins server = 10.0.0.18 to your <code class="filename">smb.conf</code> file <em class="parameter"><code>[global]</code></em> section.
</p><div class="important" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Important</h3><p>
Never use <a class="indexterm" name="id348276"></a>wins support = yes together with <a class="indexterm" name="id348283"></a>wins server = 10.0.0.18 particularly not using its own IP address. Specifying both will cause <span class="application">nmbd</span>
to refuse to start!
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id348298"></a>WINS Server Configuration</h3></div></div></div><p>
<a class="indexterm" name="id348306"></a>
Either a Samba server or a Windows NT server machine may be set up
as a WINS server. To configure a Samba server to be a WINS server, you must
add to the <code class="filename">smb.conf</code> file on the selected Server the following line to
the <em class="parameter"><code>[global]</code></em> section:
</p><p>
</p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id348335"></a><em class="parameter"><code>wins support = yes</code></em></td></tr></table><p>
</p><p>
<a class="indexterm" name="id348351"></a>
Versions of Samba prior to 1.9.17 had this parameter default to
yes. If you have any older versions of Samba on your network, it is
strongly suggested you upgrade to a recent version, or at the very
least set the parameter to “<span class="quote">no</span>” on all these machines.
</p><p>
Machines configured with <a class="indexterm" name="id348367"></a>wins support = yes will keep a list of
all NetBIOS names registered with them, acting as a DNS for NetBIOS names.
</p><p>
<a class="indexterm" name="id348378"></a>
It is strongly recommended to set up only one WINS server. Do not set the
<a class="indexterm" name="id348385"></a>wins support = yes option on more than one Samba
server on a network.
</p><p>
<a class="indexterm" name="id348396"></a>
<a class="indexterm" name="id348405"></a>
<a class="indexterm" name="id348412"></a>
<a class="indexterm" name="id348419"></a>
<a class="indexterm" name="id348426"></a>
To configure Windows NT/200x Server as a WINS server, install and configure the WINS service. See the Windows
NT/200x documentation for details. Windows NT/200x WINS servers can replicate to each other, allowing more
than one to be set up in a complex subnet environment. Because Microsoft refuses to document the replication
protocols, Samba cannot currently participate in these replications. It is possible that a Samba-to-Samba WINS
replication protocol may be defined in the future, in which case more than one Samba machine could be set up
as a WINS server. Currently only one Samba server should have the <a class="indexterm" name="id348438"></a>wins support = yes parameter set.
</p><p>
<a class="indexterm" name="id348448"></a>
<a class="indexterm" name="id348455"></a>
After the WINS server has been configured, you must ensure that all machines participating on the network are
configured with the address of this WINS server. If your WINS server is a Samba machine, fill in the Samba
machine IP address in the <span class="guilabel">Primary WINS Server</span> field of the <span class="guilabel">Control
Panel->Network->Protocols->TCP->WINS Server</span> dialogs in Windows 9x/Me or Windows NT/200x. To tell a
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:
</p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id348495"></a><em class="parameter"><code>wins server = <name or IP address></code></em></td></tr></table><p>
where <name or IP address> is either the DNS name of the WINS server
machine or its IP address.
</p><p>
This line must not be set in the <code class="filename">smb.conf</code> file of the Samba
server acting as the WINS server itself. If you set both the
<a class="indexterm" name="id348520"></a>wins support = yes option and the
<a class="indexterm" name="id348528"></a>wins server = <name> option then
<code class="literal">nmbd</code> will fail to start.
</p><p>
<a class="indexterm" name="id348545"></a>
<a class="indexterm" name="id348551"></a>
<a class="indexterm" name="id348558"></a>
<a class="indexterm" name="id348565"></a>
There are two possible scenarios for setting up cross-subnet browsing.
The first details setting up cross-subnet browsing on a network containing
Windows 9x/Me, Samba, and Windows NT/200x machines that are not configured as
part of a Windows NT domain. The second details setting up cross-subnet
browsing on networks that contain NT domains.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id348577"></a>WINS Replication</h3></div></div></div><p>
<a class="indexterm" name="id348585"></a>
<a class="indexterm" name="id348594"></a>
Samba-3 does not support native WINS replication. There was an approach to implement it, called
<code class="filename">wrepld</code>, but it was never ready for action and the development is now discontinued.
</p><p>
Meanwhile, there is a project named <code class="filename">samba4WINS</code>, which makes it possible to
run the Samba-4 WINS server parallel to Samba-3 since version 3.0.21. More information about
<code class="filename">samba4WINS</code> are available at http://ftp.sernet.de/pub/samba4WINS.
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id348627"></a>Static WINS Entries</h3></div></div></div><p>
<a class="indexterm" name="id348635"></a>
<a class="indexterm" name="id348642"></a>
<a class="indexterm" name="id348648"></a>
<a class="indexterm" name="id348655"></a>
Adding static entries to your Samba WINS server is actually fairly easy. All you have to do is add a line to
<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>.
</p><p>
Entries in <code class="filename">wins.dat</code> take the form of:
</p><pre class="programlisting">
"NAME#TYPE" TTL ADDRESS+ FLAGS
</pre><p>
<a class="indexterm" name="id348699"></a>
<a class="indexterm" name="id348705"></a>
where NAME is the NetBIOS name, TYPE is the NetBIOS type, TTL is the time-to-live as an absolute time in
seconds, ADDRESS+ is one or more addresses corresponding to the registration, and FLAGS are the NetBIOS flags
for the registration.
</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
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
restarted. It should be noted that since the <code class="filename">wins.dat</code> file changes dynamically, <span class="application">nmbd</span>
should be stopped before editting this file. Do not forget to restart <span class="application">nmbd</span> when this file has been editted.
</p></div><p>
A typical dynamic entry looks like this:
</p><pre class="programlisting">
"MADMAN#03" 1155298378 192.168.1.2 66R
</pre><p>
To make a NetBIOS name static (permanent), simply set the TTL to 0, like this:
</p><pre class="programlisting">
"MADMAN#03" 0 192.168.1.2 66R
</pre><p>
</p><p>
<a class="indexterm" name="id348772"></a>
<a class="indexterm" name="id348778"></a>
<a class="indexterm" name="id348785"></a>
<a class="indexterm" name="id348792"></a>
<a class="indexterm" name="id348799"></a>
<a class="indexterm" name="id348806"></a>
<a class="indexterm" name="id348812"></a>
The NetBIOS flags may be interpreted as additive hexadecimal values: 00 - Broadcast node registration, 20 -
Peer node registration, 40 - Meta node registration, 60 - Hybrid node registration, 02 - Permanent name, 04 -
Active name, 80 - Group name. The 'R' indicates this is a registration record. Thus 66R means: Hybrid node
active and permanent NetBIOS name. These values may be found in the <code class="filename">nameserv.h</code> header
file from the Samba source code repository. These are the values for the NB flags.
</p><p>
<a class="indexterm" name="id348833"></a>
Though this method works with early Samba-3 versions, there is a possibility that it may change in future
versions if WINS replication is added.
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id348844"></a>Helpful Hints</h2></div></div></div><p>
The following hints should be carefully considered because they are stumbling points
for many new network administrators.
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id348854"></a>Windows Networking Protocols</h3></div></div></div><p>
<a class="indexterm" name="id348862"></a>
<a class="indexterm" name="id348869"></a>
A common cause of browsing problems results from the installation of more than one protocol on an MS Windows
machine.
</p><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p>
Do not use more than one protocol on MS Windows clients.
</p></div><p>
<a class="indexterm" name="id348885"></a>
<a class="indexterm" name="id348891"></a>
Every NetBIOS machine takes part in a process of electing the LMB (and DMB)
every 15 minutes. A set of election criteria is used to determine the order
of precedence for winning this election process. A machine running Samba or
Windows NT will be biased, so the most suitable machine will predictably
win and thus retain its role.
</p><p>
<a class="indexterm" name="id348904"></a>
<a class="indexterm" name="id348911"></a>
<a class="indexterm" name="id348918"></a>
<a class="indexterm" name="id348924"></a>
<a class="indexterm" name="id348931"></a>
<a class="indexterm" name="id348937"></a>
The election process is <span class="emphasis"><em>fought out, so to speak</em></span> over every NetBIOS network interface. In
the case of a Windows 9x/Me machine that has both TCP/IP and IPX installed and has NetBIOS enabled over both
protocols, the election will be decided over both protocols. As often happens, if the Windows 9x/Me machine is
the only one with both protocols, then the LMB may be won on the NetBIOS interface over the IPX protocol.
Samba will then lose the LMB role because Windows 9x/Me will insist it knows who the LMB is. Samba will then
cease to function as an LMB, and browse list operation on all TCP/IP-only machines will therefore fail.
</p><p>
<a class="indexterm" name="id348956"></a>
<a class="indexterm" name="id348963"></a>
Windows 95, 98, 98se, and Me are referred to generically as Windows 9x/Me.
The Windows NT4, 200x, and XP use common protocols. These are roughly
referred to as the Windows NT family, but it should be recognized that 2000 and
XP/2003 introduce new protocol extensions that cause them to behave
differently from MS Windows NT4. Generally, where a server does not support
the newer or extended protocol, these will fall back to the NT4 protocols.
</p><p>
The safest rule of all to follow is: Use only one protocol!
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id348980"></a>Name Resolution Order</h3></div></div></div><p>
<a class="indexterm" name="id348987"></a>
<a class="indexterm" name="id348994"></a>
Resolution of NetBIOS names to IP addresses can take place using a number
of methods. The only ones that can provide NetBIOS name_type information
are:
</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>
Alternative means of name resolution include:
</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>
<a class="indexterm" name="id349059"></a>
<a class="indexterm" name="id349066"></a>
Many sites want to restrict DNS lookups and avoid broadcast name
resolution traffic. The <em class="parameter"><code>name resolve order</code></em> parameter is of great help here.
The syntax of the <em class="parameter"><code>name resolve order</code></em> parameter is:
</p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id349091"></a><em class="parameter"><code>name resolve order = wins lmhosts bcast host</code></em></td></tr></table><p>
<span class="emphasis"><em>or</em></span>
</p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id349113"></a><em class="parameter"><code>name resolve order = wins lmhosts (eliminates bcast and host)</code></em></td></tr></table><p>
The default is:
</p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id349131"></a><em class="parameter"><code>name resolve order = host lmhost wins bcast</code></em></td></tr></table><p>
<a class="indexterm" name="id349144"></a>
where “<span class="quote">host</span>” refers to the native methods used by the UNIX system to implement the
gethostbyname() function call. This is normally controlled by <code class="filename">/etc/host.conf</code>,
<code class="filename">/etc/nsswitch.conf</code> and <code class="filename">/etc/resolv.conf</code>.
</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id349177"></a>Technical Overview of Browsing</h2></div></div></div><p>
<a class="indexterm" name="id349185"></a>
SMB networking provides a mechanism by which clients can access a list
of machines in a network called <a class="indexterm" name="id349192"></a>browse list. This list
contains machines that are ready to offer file and/or print services
to other machines within the network. It therefore does not include
machines that aren't currently able to do server tasks. The browse
list is heavily used by all SMB clients. Configuration of SMB
browsing has been problematic for some Samba users, hence this
document.
</p><p>
<a class="indexterm" name="id349205"></a>
<a class="indexterm" name="id349212"></a>
<a class="indexterm" name="id349219"></a>
MS Windows 2000 and later versions, as with Samba-3 and later versions, can be
configured to not use NetBIOS over TCP/IP. When configured this way,
it is imperative that name resolution (using DNS/LDAP/ADS) be correctly
configured and operative. Browsing will not work if name resolution
from SMB machine names to IP addresses does not function correctly.
</p><p>
<a class="indexterm" name="id349232"></a>
<a class="indexterm" name="id349239"></a>
Where NetBIOS over TCP/IP is enabled, use of a WINS server is highly
recommended to aid the resolution of NetBIOS (SMB) names to IP addresses.
WINS allows remote segment clients to obtain NetBIOS name_type information
that cannot be provided by any other means of name resolution.
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id349249"></a>Browsing Support in Samba</h3></div></div></div><p>
<a class="indexterm" name="id349257"></a>
<a class="indexterm" name="id349264"></a>
<a class="indexterm" name="id349270"></a>
<a class="indexterm" name="id349277"></a>
Samba facilitates browsing. The browsing is supported by <span class="application">nmbd</span>
and is also controlled by options in the <code class="filename">smb.conf</code> file.
Samba can act as an LMB for a workgroup, and the ability
to support domain logons and scripts is now available.
</p><p>
<a class="indexterm" name="id349301"></a>
<a class="indexterm" name="id349308"></a>
<a class="indexterm" name="id349314"></a>
Samba can also act as a DMB for a workgroup. This
means that it will collate lists from LMBs into a
wide-area network server list. In order for browse clients to
resolve the names they may find in this list, it is recommended that
both Samba and your clients use a WINS server.
</p><p>
<a class="indexterm" name="id349327"></a>
Do not set Samba to be the domain master for a workgroup that has the same
name as an NT Domain. On each wide-area network, you must only ever have one
DMB per workgroup, regardless of whether it is NT, Samba,
or any other type of domain master that is providing this service.
</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
<a class="indexterm" name="id349340"></a>
<a class="indexterm" name="id349347"></a>
<code class="literal">nmbd</code> can be configured as a WINS server, but it is not
necessary to specifically use Samba as your WINS server. MS Windows
NT4, Server or Advanced Server 200x can be configured as
your WINS server. In a mixed NT/200x server and Samba environment on
a WAN, it is recommended that you use the Microsoft
WINS server capabilities. In a Samba-only environment, it is
recommended that you use one and only one Samba server as the WINS server.
</p></div><p>
<a class="indexterm" name="id349366"></a>
To get browsing to work, you need to run <code class="literal">nmbd</code> as usual, but must
use the <a class="indexterm" name="id349380"></a>workgroup option in <code class="filename">smb.conf</code>
to control what workgroup Samba becomes a part of.
</p><p>
<a class="indexterm" name="id349396"></a>
Samba also has a useful option for a Samba server to offer itself for
browsing on another subnet. It is recommended that this option is
used only for “<span class="quote">unusual</span>” purposes: announcements over the Internet, for
example. See <a class="indexterm" name="id349409"></a>remote announce 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="id349424"></a>Problem Resolution</h3></div></div></div><p>
<a class="indexterm" name="id349432"></a>
<a class="indexterm" name="id349439"></a>
If something does not work, the <code class="filename">log.nmbd</code> file will help
to track down the problem. Try a <a class="indexterm" name="id349452"></a>log level of 2 or 3 for finding
problems. Also note that the current browse list usually gets stored
in text form in a file called <code class="filename">browse.dat</code>.
</p><p>
<a class="indexterm" name="id349469"></a>
<a class="indexterm" name="id349476"></a>
If it does not work, you should still be able to
type the server name as <code class="filename">\\SERVER</code> in <code class="literal">filemanager</code>, then
press enter, and <code class="literal">filemanager</code> should display the list of available shares.
</p><p>
<a class="indexterm" name="id349505"></a>
<a class="indexterm" name="id349512"></a>
Some people find browsing fails because they do not have the global
<a class="indexterm" name="id349519"></a>guest account set to a valid account. Remember that the
IPC$ connection that lists the shares is done as guest and so you must have a valid guest account.
</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
<a class="indexterm" name="id349532"></a>
<a class="indexterm" name="id349539"></a>
<a class="indexterm" name="id349545"></a>
<a class="indexterm" name="id349552"></a>
<a class="indexterm" name="id349559"></a>
The <code class="literal">IPC$</code> share is used by all SMB/CIFS clients to obtain the list of resources
that is available on the server. This is the source of the list of shares and printers when browsing
an SMB/CIFS server (also Windows machines) using the Windows Explorer to browse resources through
the Windows Network Neighborhood (also called My Network Places) through to a Windows server. At
this point, the client has opened a connection to the <code class="literal">\\server\IPC4</code> resource.
Clicking on a share will then open up a connection to the <code class="literal">\\server\share</code>.
</p></div><p>
<a class="indexterm" name="id349591"></a>
<a class="indexterm" name="id349598"></a>
<a class="indexterm" name="id349604"></a>
<a class="indexterm" name="id349611"></a>
MS Windows 2000 and later (as with Samba) can be configured to disallow
anonymous (i.e., guest account) access to the IPC$ share. In that case, the
MS Windows 2000/XP/2003 machine acting as an SMB/CIFS client will use the
name of the currently logged-in user to query the IPC$ share. MS Windows
9x/Me clients are not able to do this and thus will not be able to browse
server resources.
</p><p>
<a class="indexterm" name="id349624"></a>
The other big problem people have is that their broadcast address,
netmask, or IP address is wrong (specified with the <a class="indexterm" name="id349632"></a>interfaces option
in <code class="filename">smb.conf</code>)
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id349647"></a>Cross-Subnet Browsing</h3></div></div></div><p>
<a class="indexterm" name="id349655"></a>
<a class="indexterm" name="id349664"></a>
Since the release of Samba 1.9.17 (alpha1), Samba has supported the replication of browse lists across subnet
boundaries. This section describes how to set this feature up in different settings.
</p><p>
<a class="indexterm" name="id349676"></a>
<a class="indexterm" name="id349683"></a>
<a class="indexterm" name="id349690"></a>
<a class="indexterm" name="id349696"></a>
<a class="indexterm" name="id349703"></a>
<a class="indexterm" name="id349710"></a>
To see browse lists that span TCP/IP subnets (i.e., networks separated by routers that do not pass broadcast
traffic), you must set up at least one WINS server. The WINS server acts as a DNS for NetBIOS names. This will
allow NetBIOS name-to-IP address translation to be completed by a direct query of the WINS server. This is
done via a directed UDP packet on port 137 to the WINS server machine. The WINS server avoids the necessity of
default NetBIOS name-to-IP address translation, which is done using UDP broadcasts from the querying machine.
This means that machines on one subnet will not be able to resolve the names of machines on another subnet
without using a WINS server. The Samba hacks, <em class="parameter"><code>remote browse sync</code></em>, and <em class="parameter"><code>remote
announce</code></em> are designed to get around the natural limitations that prevent UDP broadcast
propagation. The hacks are not a universal solution and they should not be used in place of WINS, they are
considered last resort methods.
</p><p>
<a class="indexterm" name="id349740"></a>
<a class="indexterm" name="id349746"></a>
<a class="indexterm" name="id349753"></a>
<a class="indexterm" name="id349760"></a>
Remember, for browsing across subnets to work correctly, all machines, be they Windows 95, Windows NT, or
Samba servers, must have the IP address of a WINS server given to them by a DHCP server or by manual
configuration: for Windows 9x/Me and Windows NT/200x/XP, this is in the TCP/IP Properties, under Network
settings; for Samba, this is in the <code class="filename">smb.conf</code> file.
</p><p>
<a class="indexterm" name="id349779"></a>
<a class="indexterm" name="id349786"></a>
<a class="indexterm" name="id349792"></a>
It is possible to operate Samba-3 without NetBIOS over TCP/IP. If you do this, be warned that if used outside
of MS ADS, this will forgo network browsing support. ADS permits network browsing support through DNS,
providing appropriate DNS records are inserted for all Samba servers.
</p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id349802"></a>Behavior of Cross-Subnet Browsing</h4></div></div></div><p>
<a class="indexterm" name="id349810"></a>
<a class="indexterm" name="id349817"></a>
Cross-subnet browsing is a complicated dance, containing multiple moving parts. It has taken Microsoft several
years to get the code that correctly achieves this, and Samba lags behind in some areas. Samba is capable of
cross-subnet browsing when configured correctly.
</p><p>
Consider a network set up as in <a href="NetworkBrowsing.html#browsing1" title="Figure 10.1. Cross-Subnet Browsing Example.">Cross-Subnet Browsing Example</a>.
</p><div class="figure"><a name="browsing1"></a><p class="title"><b>Figure 10.1. Cross-Subnet Browsing Example.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/browsing1.png" width="216" alt="Cross-Subnet Browsing Example."></div></div></div><br class="figure-break"><p>
<a class="indexterm" name="id349881"></a>
<a class="indexterm" name="id349887"></a>
<a class="indexterm" name="id349894"></a>
This consists of three subnets (1, 2, 3) connected by two routers (R1, R2), which do not pass broadcasts.
Subnet 1 has five machines on it, subnet 2 has four machines, and subnet 3 has four machines. Assume for the
moment that all machines are configured to be in the same workgroup (for simplicity's sake). Machine N1_C on
subnet 1 is configured as the DMB (i.e., it will collate the browse lists for the workgroup). Machine N2_D is
configured as a WINS server, and all the other machines are configured to register their NetBIOS names with
it.
</p><p>
<a class="indexterm" name="id349909"></a>
<a class="indexterm" name="id349915"></a>
<a class="indexterm" name="id349922"></a>
As these machines are booted up, elections for master browsers
take place on each of the three subnets. Assume that machine
N1_C wins on subnet 1, N2_B wins on subnet 2, and N3_D wins on
subnet 3. These machines are known as LMBs for
their particular subnet. N1_C has an advantage in winning as the
LMB on subnet 1 because it is set up as DMB.
</p><p>
<a class="indexterm" name="id349935"></a>
<a class="indexterm" name="id349941"></a>
On each of the three networks, machines that are configured to
offer sharing services will broadcast that they are offering
these services. The LMB on each subnet will
receive these broadcasts and keep a record of the fact that
the machine is offering a service. This list of records is
the basis of the browse list. For this case, assume that
all the machines are configured to offer services, so all machines
will be on the browse list.
</p><p>
<a class="indexterm" name="id349955"></a>
<a class="indexterm" name="id349962"></a>
<a class="indexterm" name="id349968"></a>
<a class="indexterm" name="id349975"></a>
<a class="indexterm" name="id349982"></a>
For each network, the LMB on that network is
considered <span class="emphasis"><em>authoritative</em></span> for all the names it receives via
local broadcast. This is because a machine seen by the LMB
via a local broadcast must be on the same network as the
Local Master Browser and thus is a <span class="emphasis"><em>trusted</em></span>
and <span class="emphasis"><em>verifiable</em></span> resource. Machines on other networks that
the LMBs learn about when collating their
browse lists have not been directly seen. These records are
called <span class="emphasis"><em>non-authoritative.</em></span>
</p><p>
<a class="indexterm" name="id350010"></a>
At this point the browse lists appear as shown in <a href="NetworkBrowsing.html#browsubnet" title="Table 10.1. Browse Subnet Example 1">Browse Subnet Example 1</a> (these are
the machines you would see in your network neighborhood if you looked in it on a particular network right now).
</p><p>
</p><div class="table"><a name="browsubnet"></a><p class="title"><b>Table 10.1. Browse Subnet Example 1</b></p><div class="table-contents"><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></div><p><br class="table-break">
</p><p>
At this point all the subnets are separate, and no machine is seen across any of the subnets.
</p><p>
<a class="indexterm" name="id350100"></a>
<a class="indexterm" name="id350107"></a>
<a class="indexterm" name="id350114"></a>
<a class="indexterm" name="id350120"></a>
Now examine subnet 2 in <a href="NetworkBrowsing.html#brsbex" title="Table 10.2. Browse Subnet Example 2">Browse Subnet Example 2</a>.
As soon as N2_B has become the LMB, it looks for a DMB with which to synchronize
its browse list. It does this by querying the WINS server
(N2_D) for the IP address associated with the NetBIOS name
WORKGROUP<1B>. This name was registered by the DMB
(N1_C) with the WINS server as soon as it was started.
</p><p>
<a class="indexterm" name="id350142"></a>
<a class="indexterm" name="id350149"></a>
<a class="indexterm" name="id350155"></a>
<a class="indexterm" name="id350162"></a>
Once N2_B knows the address of the DMB, it
tells it that is the LMB for subnet 2 by
sending a <span class="emphasis"><em>MasterAnnouncement</em></span> packet as a UDP port 138 packet.
It then synchronizes with it by doing a <span class="emphasis"><em>NetServerEnum2</em></span> call. This
tells the DMB to send it all the server
names it knows about. Once the DMB receives
the <span class="emphasis"><em>MasterAnnouncement</em></span> packet, it schedules a synchronization
request to the sender of that packet. After both synchronizations
are complete, the browse lists look like those in <a href="NetworkBrowsing.html#brsbex" title="Table 10.2. Browse Subnet Example 2">Browse Subnet Example 2</a>
</p><div class="table"><a name="brsbex"></a><p class="title"><b>Table 10.2. Browse Subnet Example 2</b></p><div class="table-contents"><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,
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(*),
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></div><br class="table-break"><p>
<a class="indexterm" name="id350270"></a>
Servers with an (*) after them are non-authoritative names.
</p><p>
<a class="indexterm" name="id350281"></a>
At this point users looking in their Network Neighborhood on
subnets 1 or 2 will see all the servers on both; users on
subnet 3 will still see only the servers on their own subnet.
</p><p>
<a class="indexterm" name="id350292"></a>
The same sequence of events that occurred for N2_B now occurs
for the LMB on subnet 3 (N3_D). When it
synchronizes browse lists with the DMB (N1_A)
it gets both the server entries on subnet 1 and those on
subnet 2. After N3_D has synchronized with N1_C and vica versa,
the browse lists will appear as shown in <a href="NetworkBrowsing.html#brsex2" title="Table 10.3. Browse Subnet Example 3">Browse Subnet Example 3</a>
</p><div class="table"><a name="brsex2"></a><p class="title"><b>Table 10.3. Browse Subnet Example 3</b></p><div class="table-contents"><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="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,
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="justify">N2_A, N2_B, N2_C, N2_D, N1_A(*),
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, N1_A(*),
N1_B(*), N1_C(*), N1_D(*), N1_E(*), N2_A(*), N2_B(*), N2_C(*), N2_D(*)</td></tr></tbody></table></div></div><br class="table-break"><p>
Servers with an (*) after them are non-authoritative names.
</p><p>
At this point, users looking in their Network Neighborhood on
subnets 1 or 3 will see all the servers on all subnets, while users on
subnet 2 will still see only the servers on subnets 1 and 2, but not 3.
</p><p>
<a class="indexterm" name="id350401"></a>
<a class="indexterm" name="id350408"></a>
<a class="indexterm" name="id350414"></a>
Finally, the LMB for subnet 2 (N2_B) will sync again
with the DMB (N1_C) and will receive the missing
server entries. Finally, as when a steady state (if no machines
are removed or shut off) has been achieved, the browse lists will appear
as shown in <a href="NetworkBrowsing.html#brsex3" title="Table 10.4. Browse Subnet Example 4">Browse Subnet Example 4</a>.
</p><div class="table"><a name="brsex3"></a><p class="title"><b>Table 10.4. Browse Subnet Example 4</b></p><div class="table-contents"><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="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,
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="justify">N2_A, N2_B, N2_C, N2_D, N1_A(*),
N1_B(*), N1_C(*), N1_D(*), N1_E(*), N3_A(*), N3_B(*),
N3_C(*), N3_D(*)</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, N1_A(*),
N1_B(*), N1_C(*), N1_D(*), N1_E(*), N2_A(*), N2_B(*),
N2_C(*), N2_D(*)</td></tr></tbody></table></div></div><br class="table-break"><p>
Servers with an (*) after them are non-authoritative names.
</p><p>
Synchronizations between the DMB and LMBs
will continue to occur, but this should remain a
steady-state operation.
</p><p>
If either router R1 or R2 fails, the following will occur:
</p><div class="orderedlist"><ol type="1"><li><p>
<a class="indexterm" name="id350536"></a>
Names of computers on each side of the inaccessible network fragments
will be maintained for as long as 36 minutes in the Network Neighborhood
lists.
</p></li><li><p>
Attempts to connect to these inaccessible computers will fail, but the
names will not be removed from the Network Neighborhood lists.
</p></li><li><p>
<a class="indexterm" name="id350559"></a>
<a class="indexterm" name="id350565"></a>
<a class="indexterm" name="id350572"></a>
If one of the fragments is cut off from the WINS server, it will only
be able to access servers on its local subnet using subnet-isolated
broadcast NetBIOS name resolution. The effect is similar to that of
losing access to a DNS server.
</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="id350588"></a>Common Errors</h2></div></div></div><p>
<a class="indexterm" name="id350595"></a>
<a class="indexterm" name="id350602"></a>
Many questions are asked on the mailing lists regarding browsing. The majority of browsing
problems originate from incorrect configuration of NetBIOS name resolution. Some are of
particular note.
</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id350612"></a>Flushing the Samba NetBIOS Name Cache</h3></div></div></div><p>
How Can One Flush the Samba NetBIOS Name Cache without Restarting Samba?
</p><p>
<a class="indexterm" name="id350624"></a>
<a class="indexterm" name="id350630"></a>
<a class="indexterm" name="id350637"></a>
<a class="indexterm" name="id350644"></a>
Samba's <code class="literal">nmbd</code> process controls all browse list handling. Under normal circumstances it is
safe to restart <code class="literal">nmbd</code>. This will effectively flush the Samba NetBIOS name cache and cause it
to be rebuilt. This does not make certain that a rogue machine name will not reappear
in the browse list. When <code class="literal">nmbd</code> is taken out of service, another machine on the network will
become the browse master. This new list may still have the rogue entry in it. If you really
want to clear a rogue machine from the list, every machine on the network must be
shut down and restarted after all machines are down. Failing a complete restart, the only
other thing you can do is wait until the entry times out and is then flushed from the list.
This may take a long time on some networks (perhaps months).
</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id350677"></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>
Your guest account is probably invalid for some reason. Samba uses the
guest account for browsing in <code class="literal">smbd</code>. Check that your guest account is
valid.
</p><p>Also see <a class="indexterm" name="id350703"></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="id350718"></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:
<a class="indexterm" name="id350730"></a>
</p><div class="itemizedlist"><ul type="disc"><li><p>There is no LMB. Configure <span class="application">nmbd</span>
or any other machine to serve as LMB.</p></li><li><p>You cannot log onto the machine that is the LMB.
Can you log on to it as a guest user? </p></li><li><p>There is no IP connectivity to the LMB.
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="id350764"></a>Browsing of Shares and Directories is Very Slow</h3></div></div></div><p>“<span class="quote">
<a class="indexterm" name="id350773"></a>
There are only two machines on a test network. One is a Samba server, the other a Windows XP machine.
Authentication and logons work perfectly, but when I try to explore shares on the Samba server, the
Windows XP client becomes unresponsive. Sometimes it does not respond for some minutes. Eventually,
Windows Explorer will respond and displays files and directories without problem.
</span>”
</p><p>“<span class="quote">
<a class="indexterm" name="id350788"></a>
But, the share is immediately available from a command shell (<code class="literal">cmd</code>, followed by
exploration with DOS command. Is this a Samba problem, or is it a Windows problem? How can I solve this?
</span>”</p><p>
Here are a few possibilities:
</p><div class="variablelist"><dl><dt><span class="term">Bad Networking Hardware</span></dt><dd><p>
<a class="indexterm" name="id350818"></a>
<a class="indexterm" name="id350825"></a>
<a class="indexterm" name="id350832"></a>
<a class="indexterm" name="id350838"></a>
<a class="indexterm" name="id350845"></a>
Most common defective hardware problems center around low cost or defective hubs, routers,
network interface controllers (NICs), and bad wiring. If one piece of hardware is defective,
the whole network may suffer. Bad networking hardware can cause data corruption. Most bad
networking hardware problems are accompanied by an increase in apparent network traffic,
but not all.
</p></dd><dt><span class="term">The Windows XP WebClient</span></dt><dd><p>
<a class="indexterm" name="id350866"></a>
A number of sites have reported similar slow network browsing problems and found that when
the WebClient service is turned off, the problem disappears. This is certainly something
that should be explored because it is a simple solution if it works.
</p></dd><dt><span class="term">Inconsistent WINS Configuration</span></dt><dd><p>
<a class="indexterm" name="id350889"></a>
<a class="indexterm" name="id350896"></a>
This type of problem is common when one client is configured to use a WINS server (that is
a TCP/IP configuration setting) and there is no WINS server on the network. Alternatively,
this will happen if there is a WINS server and Samba is not configured to use it. The use of
WINS is highly recommended if the network is using NetBIOS over TCP/IP protocols. If use
of NetBIOS over TCP/IP is disabled on all clients, Samba should not be configured as a WINS
server, nor should it be configured to use one.
</p></dd><dt><span class="term">Incorrect DNS Configuration</span></dt><dd><p>
<a class="indexterm" name="id350918"></a>
<a class="indexterm" name="id350925"></a>
If use of NetBIOS over TCP/IP is disabled, Active Directory is in use and the DNS server
has been incorrectly configured. For further information refer to
<a href="NetworkBrowsing.html#adsdnstech" title="DNS and Active Directory">DNS and Active Directory</a>.
</p></dd></dl></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id350945"></a>Invalid Cached Share References Affects Network Browsing</h3></div></div></div><p>
Cached references on your MS Windows client (workstation or server) to shares or servers that no longer exist
can cause MS Windows Explorer to appear unresponsive as it tries to connect to these shares. After a delay
(can take a long time) it times out and browsing will appear to be mostly normal again.
</p><p>
To eliminate the problem the stale cached references should be removed. This does not happen automatically and
requires manual intervention. This is a design feature of MS Windows and not anything that Samba can change.
To remove the stale shortcuts found in <span class="emphasis"><em>My Network Places</em></span> which refer to what are now
invalid shares or servers it is necessary to edit the Windows Registry under
<code class="literal">HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\</code>. Edit the entry
<code class="literal">MountPoints2</code> (on Windows XP and later, or <code class="literal">MountPoints</code> on Windows 2000
and earlier). Remove all keys named <code class="literal">\\server\share</code> (where 'server' and 'share' refer to a
non-existent server or share). Note that this must be done for every user profile that has such stale
references. Alternately, you can delete the shortcuts from the MS Windows Explorer in <code class="literal">My Network
Places</code> just by right-clicking them and selecting <span class="emphasis"><em>Delete.</em></span>
</p><p>
Samba users have reported that these stale references negatively affect network browsing with Windows, Samba,
and Novell servers. It is suspected to be a universal problem not directly related to the Samba
server. Samba users may experience this more often due to Samba being somewhat viewed as an experimenter's
toolkit. This results from the fact that a user might go through several reconfigurations and incarnations of
their Samba server, by different names, with different shares, increasing the chances for having stale
(invalid) cached share references. Windows clients do not seem to expire these references.
</p><p>
It is common for <span class="emphasis"><em>Open</em></span> dialog boxes (for example; in Word and Excel) to respond very
slowly, as they attempt to locate all of the cached references, even if they are not in the current directory
being accessed.
</p></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ChangeNotes.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">Chapter 9. Important Samba-3.0.23 Change Notes </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 11. Account Information Databases</td></tr></table></div></body></html>