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diff --git a/docs/htmldocs/Samba3-HOWTO/integrate-ms-networks.html b/docs/htmldocs/Samba3-HOWTO/integrate-ms-networks.html new file mode 100644 index 0000000000..2082c08cc7 --- /dev/null +++ b/docs/htmldocs/Samba3-HOWTO/integrate-ms-networks.html @@ -0,0 +1,461 @@ +<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter 29. Integrating MS Windows Networks with Samba</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="pam.html" title="Chapter 28. PAM-Based Distributed Authentication"><link rel="next" href="unicode.html" title="Chapter 30. Unicode/Charsets"></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 29. Integrating MS Windows Networks with Samba</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="pam.html">Prev</a> </td><th width="60%" align="center">Part III. Advanced Configuration</th><td width="20%" align="right"> <a accesskey="n" href="unicode.html">Next</a></td></tr></table><hr></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="integrate-ms-networks"></a>Chapter 29. Integrating MS Windows Networks with Samba</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><p class="pubdate"> (Jan 01 2001) </p></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="integrate-ms-networks.html#id424744">Features and Benefits</a></span></dt><dt><span class="sect1"><a href="integrate-ms-networks.html#id424761">Background Information</a></span></dt><dt><span class="sect1"><a href="integrate-ms-networks.html#id424880">Name Resolution in a Pure UNIX/Linux World</a></span></dt><dd><dl><dt><span class="sect2"><a href="integrate-ms-networks.html#id424951"><code class="filename">/etc/hosts</code></a></span></dt><dt><span class="sect2"><a href="integrate-ms-networks.html#id425107"><code class="filename">/etc/resolv.conf</code></a></span></dt><dt><span class="sect2"><a href="integrate-ms-networks.html#id425140"><code class="filename">/etc/host.conf</code></a></span></dt><dt><span class="sect2"><a href="integrate-ms-networks.html#id425188"><code class="filename">/etc/nsswitch.conf</code></a></span></dt></dl></dd><dt><span class="sect1"><a href="integrate-ms-networks.html#id425298">Name Resolution as Used within MS Windows Networking</a></span></dt><dd><dl><dt><span class="sect2"><a href="integrate-ms-networks.html#id425691">The NetBIOS Name Cache</a></span></dt><dt><span class="sect2"><a href="integrate-ms-networks.html#id425770">The LMHOSTS File</a></span></dt><dt><span class="sect2"><a href="integrate-ms-networks.html#id425896">HOSTS File</a></span></dt><dt><span class="sect2"><a href="integrate-ms-networks.html#id425921">DNS Lookup</a></span></dt><dt><span class="sect2"><a href="integrate-ms-networks.html#id425943">WINS Lookup</a></span></dt></dl></dd><dt><span class="sect1"><a href="integrate-ms-networks.html#id426077">Common Errors</a></span></dt><dd><dl><dt><span class="sect2"><a href="integrate-ms-networks.html#id426088">Pinging Works Only One Way</a></span></dt><dt><span class="sect2"><a href="integrate-ms-networks.html#id426116">Very Slow Network Connections</a></span></dt><dt><span class="sect2"><a href="integrate-ms-networks.html#id426154">Samba Server Name-Change Problem</a></span></dt></dl></dd></dl></div><p> +<a class="indexterm" name="id424707"></a> +This chapter deals with NetBIOS over TCP/IP name to IP address resolution. If +your MS Windows clients are not configured to use NetBIOS over TCP/IP, then this +section does not apply to your installation. If your installation involves the use of +NetBIOS over TCP/IP, then this chapter may help you to resolve networking problems. +</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p> +<a class="indexterm" name="id424722"></a> +<a class="indexterm" name="id424729"></a> +NetBIOS over TCP/IP has nothing to do with NetBEUI. NetBEUI is NetBIOS +over Logical Link Control (LLC). On modern networks it is highly advised +to not run NetBEUI at all. Note also that there is no such thing as +NetBEUI over TCP/IP the existence of such a protocol is a complete +and utter misapprehension. +</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id424744"></a>Features and Benefits</h2></div></div></div><p> +Many MS Windows network administrators have never been exposed to basic TCP/IP +networking as it is implemented in a UNIX/Linux operating system. Likewise, many UNIX and +Linux administrators have not been exposed to the intricacies of MS Windows TCP/IP-based +networking (and may have no desire to be, either). +</p><p> +This chapter gives a short introduction to the basics of how a name can be resolved to +its IP address for each operating system environment. +</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id424761"></a>Background Information</h2></div></div></div><p> +<a class="indexterm" name="id424768"></a> +<a class="indexterm" name="id424775"></a> +<a class="indexterm" name="id424782"></a> +<a class="indexterm" name="id424789"></a> +<a class="indexterm" name="id424796"></a> +Since the introduction of MS Windows 2000, it is possible to run MS Windows networking +without the use of NetBIOS over TCP/IP. NetBIOS over TCP/IP uses UDP port 137 for NetBIOS +name resolution and uses TCP port 139 for NetBIOS session services. When NetBIOS over +TCP/IP is disabled on MS Windows 2000 and later clients, then only the TCP port 445 is +used, and the UDP port 137 and TCP port 139 are not. +</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p> +When using Windows 2000 or later clients, if NetBIOS over TCP/IP is not disabled, then +the client will use UDP port 137 (NetBIOS Name Service, also known as the Windows Internet +Name Service, or WINS), TCP port 139, and TCP port 445 (for actual file and print traffic). +</p></div><p> +<a class="indexterm" name="id424818"></a> +<a class="indexterm" name="id424824"></a> +<a class="indexterm" name="id424831"></a> +<a class="indexterm" name="id424838"></a> +<a class="indexterm" name="id424844"></a> +<a class="indexterm" name="id424851"></a> +When NetBIOS over TCP/IP is disabled, the use of DNS is essential. Most installations that disable NetBIOS +over TCP/IP today use MS Active Directory Service (ADS). ADS requires +<a class="indexterm" name="id424860"></a> dynamic DNS with Service Resource +Records (SRV RR) and with Incremental Zone Transfers (IXFR). <a class="indexterm" name="id424870"></a> +Use of DHCP with ADS is recommended as a further means of maintaining central control over the client +workstation network configuration. +</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id424880"></a>Name Resolution in a Pure UNIX/Linux World</h2></div></div></div><p> +The key configuration files covered in this section are: +</p><a class="indexterm" name="id424890"></a><a class="indexterm" name="id424896"></a><a class="indexterm" name="id424903"></a><a class="indexterm" name="id424910"></a><div class="itemizedlist"><ul type="disc"><li><p><code class="filename">/etc/hosts</code></p></li><li><p><code class="filename">/etc/resolv.conf</code></p></li><li><p><code class="filename">/etc/host.conf</code></p></li><li><p><code class="filename">/etc/nsswitch.conf</code></p></li></ul></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id424951"></a><code class="filename">/etc/hosts</code></h3></div></div></div><p> +This file contains a static list of IP addresses and names. +</p><pre class="programlisting"> +127.0.0.1 localhost localhost.localdomain +192.168.1.1 bigbox.quenya.org bigbox alias4box +</pre><p> +</p><p> +<a class="indexterm" name="id424973"></a> +<a class="indexterm" name="id424980"></a> +The purpose of <code class="filename">/etc/hosts</code> is to provide a +name resolution mechanism so users do not need to remember +IP addresses. +</p><p> +<a class="indexterm" name="id424996"></a> +<a class="indexterm" name="id425003"></a> +<a class="indexterm" name="id425010"></a> +Network packets that are sent over the physical network transport +layer communicate not via IP addresses but rather using the Media +Access Control address, or MAC address. IP addresses are currently +32 bits in length and are typically presented as four decimal +numbers that are separated by a dot (or period) for example, 168.192.1.1. +</p><p> +<a class="indexterm" name="id425026"></a> +MAC addresses use 48 bits (or 6 bytes) and are typically represented +as two-digit hexadecimal numbers separated by colons: 40:8e:0a:12:34:56. +</p><p> +Every network interface must have a MAC address. Associated with a MAC address may be one or more IP +addresses. There is no relationship between an IP address and a MAC address; all such assignments are +arbitrary or discretionary in nature. At the most basic level, all network communications take place using MAC +addressing. Since MAC addresses must be globally unique and generally remain fixed for any particular +interface, the assignment of an IP address makes sense from a network management perspective. More than one IP +address can be assigned per MAC address. One address must be the primary IP address this is the +address that will be returned in the Address Resolution Protocol (ARP) reply. +</p><p> +<a class="indexterm" name="id425049"></a> +When a user or a process wants to communicate with another machine, +the protocol implementation ensures that the “<span class="quote">machine name</span>” or “<span class="quote">host +name</span>” is resolved to an IP address in a manner that is controlled +by the TCP/IP configuration control files. The file +<code class="filename">/etc/hosts</code> is one such file. +</p><p> +<a class="indexterm" name="id425074"></a> +When the IP address of the destination interface has been determined, a protocol called ARP/RARP is used to +identify the MAC address of the target interface. ARP is a broadcast-oriented method that uses User Datagram +Protocol (UDP) to send a request to all interfaces on the local network segment using the all 1s MAC address. +Network interfaces are programmed to respond to two MAC addresses only; their own unique address and the +address ff:ff:ff:ff:ff:ff. The reply packet from an ARP request will contain the MAC address and the primary +IP address for each interface. +</p><p> +<a class="indexterm" name="id425089"></a> +The <code class="filename">/etc/hosts</code> file is foundational to all +UNIX/Linux TCP/IP installations and as a minimum will contain +the localhost and local network interface IP addresses and the +primary names by which they are known within the local machine. +This file helps to prime the pump so a basic level of name +resolution can exist before any other method of name resolution +becomes available. +</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id425107"></a><code class="filename">/etc/resolv.conf</code></h3></div></div></div><p> +This file tells the name resolution libraries: +</p><div class="itemizedlist"><ul type="disc"><li><p>The name of the domain to which the machine + belongs. + </p></li><li><p>The name(s) of any domains that should be + automatically searched when trying to resolve unqualified + host names to their IP address. + </p></li><li><p>The name or IP address of available domain + name servers that may be asked to perform name-to-address + translation lookups. + </p></li></ul></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id425140"></a><code class="filename">/etc/host.conf</code></h3></div></div></div><p> +<a class="indexterm" name="id425151"></a> +<code class="filename">/etc/host.conf</code> is the primary means by which the setting in +<code class="filename">/etc/resolv.conf</code> may be effected. It is a critical configuration file. This file controls +the order by which name resolution may proceed. The typical structure is: +</p><pre class="programlisting"> +order hosts,bind +multi on +</pre><p>Both addresses should be returned. Please refer to the +man page for <code class="filename">host.conf</code> for further details. +</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id425188"></a><code class="filename">/etc/nsswitch.conf</code></h3></div></div></div><p> +<a class="indexterm" name="id425199"></a> +This file controls the actual name resolution targets. The +file typically has resolver object specifications as follows: +</p><pre class="programlisting"> +# /etc/nsswitch.conf +# +# Name Service Switch configuration file. +# + +passwd: compat +# Alternative entries for password authentication are: +# passwd: compat files nis ldap winbind +shadow: compat +group: compat + +hosts: files nis dns +# Alternative entries for host name resolution are: +# hosts: files dns nis nis+ hesiod db compat ldap wins +networks: nis files dns + +ethers: nis files +protocols: nis files +rpc: nis files +services: nis files +</pre><p> +Of course, each of these mechanisms requires that the appropriate +facilities and/or services are correctly configured. +</p><p> +It should be noted that unless a network request/message must be +sent, TCP/IP networks are silent. All TCP/IP communications assume a +principal of speaking only when necessary. +</p><p> +<a class="indexterm" name="id425228"></a> +<a class="indexterm" name="id425235"></a> +<a class="indexterm" name="id425242"></a> +<a class="indexterm" name="id425248"></a> +<a class="indexterm" name="id425255"></a> +Starting with version 2.2.0, Samba has Linux support for extensions to +the name service switch infrastructure so Linux clients will +be able to obtain resolution of MS Windows NetBIOS names to IP +addresses. To gain this functionality, Samba needs to be compiled +with appropriate arguments to the make command (i.e., <strong class="userinput"><code>make +nsswitch/libnss_wins.so</code></strong>). The resulting library should +then be installed in the <code class="filename">/lib</code> directory, and +the <em class="parameter"><code>wins</code></em> parameter needs to be added to the “<span class="quote">hosts:</span>” line in +the <code class="filename">/etc/nsswitch.conf</code> file. At this point, it +will be possible to ping any MS Windows machine by its NetBIOS +machine name, as long as that machine is within the workgroup to +which both the Samba machine and the MS Windows machine belong. +</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id425298"></a>Name Resolution as Used within MS Windows Networking</h2></div></div></div><p> +<a class="indexterm" name="id425306"></a> +<a class="indexterm" name="id425313"></a> +<a class="indexterm" name="id425320"></a> +<a class="indexterm" name="id425326"></a> +MS Windows networking is predicated on the name each machine is given. This name is known variously (and +inconsistently) as the “<span class="quote">computer name,</span>” “<span class="quote">machine name,</span>” “<span class="quote">networking +name,</span>” “<span class="quote">NetBIOS name,</span>” or “<span class="quote">SMB name.</span>” All terms mean the same thing with the +exception of “<span class="quote">NetBIOS name,</span>” which can also apply to the name of the workgroup or the domain +name. The terms “<span class="quote">workgroup</span>” and “<span class="quote">domain</span>” are really just a simple name with which +the machine is associated. All NetBIOS names are exactly 16 characters in length. The +16<sup>th</sup> character is reserved. It is used to store a 1-byte value that indicates +service level information for the NetBIOS name that is registered. A NetBIOS machine name is therefore +registered for each service type that is provided by the client/server. +</p><p> +<a href="integrate-ms-networks.html#uniqnetbiosnames" title="Table 29.1. Unique NetBIOS Names">Unique NetBIOS names</a> and <a href="integrate-ms-networks.html#netbiosnamesgrp" title="Table 29.2. Group Names">group names</a> tables +list typical NetBIOS name/service type registrations. +</p><div class="table"><a name="uniqnetbiosnames"></a><p class="title"><b>Table 29.1. Unique NetBIOS Names</b></p><div class="table-contents"><table summary="Unique NetBIOS Names" border="1"><colgroup><col align="left"><col align="justify"></colgroup><tbody><tr><td align="left">MACHINENAME<00></td><td align="justify">Server Service is running on MACHINENAME</td></tr><tr><td align="left">MACHINENAME<03></td><td align="justify">Generic machine name (NetBIOS name)</td></tr><tr><td align="left">MACHINENAME<20></td><td align="justify">LanMan server service is running on MACHINENAME</td></tr><tr><td align="left">WORKGROUP<1b></td><td align="justify">Domain master browser</td></tr></tbody></table></div></div><br class="table-break"><div class="table"><a name="netbiosnamesgrp"></a><p class="title"><b>Table 29.2. Group Names</b></p><div class="table-contents"><table summary="Group Names" border="1"><colgroup><col align="left"><col align="justify"></colgroup><tbody><tr><td align="left">WORKGROUP<03></td><td align="justify">Generic name registered by all members of WORKGROUP</td></tr><tr><td align="left">WORKGROUP<1c></td><td align="justify">Domain cntrollers/netlogon servers</td></tr><tr><td align="left">WORKGROUP<1d></td><td align="justify">Local master browsers</td></tr><tr><td align="left">WORKGROUP<1e></td><td align="justify">Browser election service</td></tr></tbody></table></div></div><br class="table-break"><p> +<a class="indexterm" name="id425508"></a> +It should be noted that all NetBIOS machines register their own +names as per <a href="integrate-ms-networks.html#uniqnetbiosnames" title="Table 29.1. Unique NetBIOS Names">Unique NetBIOS names</a> and <a href="integrate-ms-networks.html#netbiosnamesgrp" title="Table 29.2. Group Names">group names</a>. This is in vast contrast to TCP/IP +installations where the system administrator traditionally +determines in the <code class="filename">/etc/hosts</code> or in the DNS database what names +are associated with each IP address. +</p><p> +<a class="indexterm" name="id425540"></a> +<a class="indexterm" name="id425546"></a> +<a class="indexterm" name="id425553"></a> +One further point of clarification should be noted. The <code class="filename">/etc/hosts</code> +file and the DNS records do not provide the NetBIOS name information +that MS Windows clients depend on to locate the type of service that may +be needed. An example of this is what happens when an MS Windows client +wants to locate a domain logon server. It finds this service and the IP +address of a server that provides it by performing a lookup (via a +NetBIOS broadcast) for enumeration of all machines that have +registered the name type *<1C>. A logon request is then sent to each +IP address that is returned in the enumerated list of IP addresses. +Whichever machine first replies, it then ends up providing the logon services. +</p><p> +<a class="indexterm" name="id425577"></a> +<a class="indexterm" name="id425584"></a> +The name “<span class="quote">workgroup</span>” or “<span class="quote">domain</span>” really can be confusing, since these +have the added significance of indicating what is the security +architecture of the MS Windows network. The term “<span class="quote">workgroup</span>” indicates +that the primary nature of the network environment is that of a +peer-to-peer design. In a workgroup, all machines are responsible for +their own security, and generally such security is limited to the use of +just a password (known as share-level security). In most situations +with peer-to-peer networking, the users who control their own machines +will simply opt to have no security at all. It is possible to have +user-level security in a workgroup environment, thus requiring the use +of a username and a matching password. +</p><p> +<a class="indexterm" name="id425611"></a> +<a class="indexterm" name="id425618"></a> +<a class="indexterm" name="id425627"></a> +<a class="indexterm" name="id425636"></a> +<a class="indexterm" name="id425645"></a> +<a class="indexterm" name="id425654"></a> +<a class="indexterm" name="id425661"></a> +<a class="indexterm" name="id425668"></a> +MS Windows networking is thus predetermined to use machine names +for all local and remote machine message passing. The protocol used is +called Server Message Block (SMB), and this is implemented using +the NetBIOS protocol (Network Basic Input/Output System). NetBIOS can +be encapsulated using LLC (Logical Link Control) protocol in which case +the resulting protocol is called NetBEUI (Network Basic Extended User +Interface). NetBIOS can also be run over IPX (Internetworking Packet +Exchange) protocol as used by Novell NetWare, and it can be run +over TCP/IP protocols in which case the resulting protocol is called +NBT or NetBT, the NetBIOS over TCP/IP. +</p><p> +MS Windows machines use a complex array of name resolution mechanisms. +Since we are primarily concerned with TCP/IP, this demonstration is +limited to this area. +</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id425691"></a>The NetBIOS Name Cache</h3></div></div></div><p> +<a class="indexterm" name="id425699"></a> +<a class="indexterm" name="id425706"></a> +<a class="indexterm" name="id425712"></a> +All MS Windows machines employ an in-memory buffer in which is +stored the NetBIOS names and IP addresses for all external +machines that machine has communicated with over the +past 10 to 15 minutes. It is more efficient to obtain an IP address +for a machine from the local cache than it is to go through all the +configured name resolution mechanisms. +</p><p> +<a class="indexterm" name="id425724"></a> +If a machine whose name is in the local name cache is shut +down before the name is expired and flushed from the cache, then +an attempt to exchange a message with that machine will be subject +to timeout delays. Its name is in the cache, so a name resolution +lookup will succeed, but the machine cannot respond. This can be +frustrating for users but is a characteristic of the protocol. +</p><p> +<a class="indexterm" name="id425737"></a> +<a class="indexterm" name="id425744"></a> +<a class="indexterm" name="id425751"></a> +The MS Windows utility that allows examination of the NetBIOS +name cache is called “<span class="quote">nbtstat.</span>” The Samba equivalent +is called <code class="literal">nmblookup</code>. +</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id425770"></a>The LMHOSTS File</h3></div></div></div><p> +<a class="indexterm" name="id425778"></a> +This file is usually located in MS Windows NT 4.0 or Windows 200x/XP in the directory +<code class="filename">%SystemRoot%\SYSTEM32\DRIVERS\ETC</code> and contains the IP address +and the machine name in matched pairs. The <code class="filename">LMHOSTS</code> file +performs NetBIOS name to IP address mapping. +</p><p> +It typically looks like this: +</p><pre class="programlisting"> +# Copyright (c) 1998 Microsoft Corp. +# +# This is a sample LMHOSTS file used by the Microsoft Wins Client (NetBIOS +# over TCP/IP) stack for Windows98 +# +# This file contains the mappings of IP addresses to NT computer names +# (NetBIOS) names. Each entry should be kept on an individual line. +# The IP address should be placed in the first column followed by the +# corresponding computer name. The address and the computer name +# should be separated by at least one space or tab. The "#" character +# is generally used to denote the start of a comment (see the exceptions +# below). +# +# This file is compatible with Microsoft LAN Manager 2.x TCP/IP lmhosts +# files and offers the following extensions: +# +# #PRE +# #DOM:<domain> +# #INCLUDE <filename> +# #BEGIN_ALTERNATE +# #END_ALTERNATE +# \0xnn (non-printing character support) +# +# Following any entry in the file with the characters "#PRE" will cause +# the entry to be preloaded into the name cache. By default, entries are +# not preloaded, but are parsed only after dynamic name resolution fails. +# +# Following an entry with the "#DOM:<domain>" tag will associate the +# entry with the domain specified by <domain>. This effects how the +# browser and logon services behave in TCP/IP environments. To preload +# the host name associated with #DOM entry, it is necessary to also add a +# #PRE to the line. The <domain> is always pre-loaded although it will not +# be shown when the name cache is viewed. +# +# Specifying "#INCLUDE <filename>" will force the RFC NetBIOS (NBT) +# software to seek the specified <filename> and parse it as if it were +# local. <filename> is generally a UNC-based name, allowing a +# centralized lmhosts file to be maintained on a server. +# It is ALWAYS necessary to provide a mapping for the IP address of the +# server prior to the #INCLUDE. This mapping must use the #PRE directive. +# In addition the share "public" in the example below must be in the +# LanMan Server list of "NullSessionShares" in order for client machines to +# be able to read the lmhosts file successfully. This key is under +# \machine\system\currentcontrolset\services\lanmanserver\ +# parameters\nullsessionshares +# in the registry. Simply add "public" to the list found there. +# +# The #BEGIN_ and #END_ALTERNATE keywords allow multiple #INCLUDE +# statements to be grouped together. Any single successful include +# will cause the group to succeed. +# +# Finally, non-printing characters can be embedded in mappings by +# first surrounding the NetBIOS name in quotations, then using the +# \0xnn notation to specify a hex value for a non-printing character. +# +# The following example illustrates all of these extensions: +# +# 102.54.94.97 rhino #PRE #DOM:networking #net group's DC +# 102.54.94.102 "appname \0x14" #special app server +# 102.54.94.123 popular #PRE #source server +# 102.54.94.117 localsrv #PRE #needed for the include +# +# #BEGIN_ALTERNATE +# #INCLUDE \\localsrv\public\lmhosts +# #INCLUDE \\rhino\public\lmhosts +# #END_ALTERNATE +# +# In the above example, the "appname" server contains a special +# character in its name, the "popular" and "localsrv" server names are +# pre-loaded, and the "rhino" server name is specified so it can be used +# to later #INCLUDE a centrally maintained lmhosts file if the "localsrv" +# system is unavailable. +# +# Note that the whole file is parsed including comments on each lookup, +# so keeping the number of comments to a minimum will improve performance. +# Therefore it is not advisable to simply add lmhosts file entries onto the +# end of this file. +</pre></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id425896"></a>HOSTS File</h3></div></div></div><p> +This file is usually located in MS Windows NT 4.0 or Windows 200x/XP in +the directory <code class="filename">%SystemRoot%\SYSTEM32\DRIVERS\ETC</code> and contains +the IP address and the IP hostname in matched pairs. It can be +used by the name resolution infrastructure in MS Windows, depending +on how the TCP/IP environment is configured. This file is in +every way the equivalent of the UNIX/Linux <code class="filename">/etc/hosts</code> file. +</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id425921"></a>DNS Lookup</h3></div></div></div><p> +<a class="indexterm" name="id425928"></a> +This capability is configured in the TCP/IP setup area in the network +configuration facility. If enabled, an elaborate name resolution sequence +is followed, the precise nature of which is dependent on how the NetBIOS +Node Type parameter is configured. A Node Type of 0 means that +NetBIOS broadcast (over UDP broadcast) is used if the name +that is the subject of a name lookup is not found in the NetBIOS name +cache. If that fails, then DNS, HOSTS, and LMHOSTS are checked. If set to +Node Type 8, then a NetBIOS Unicast (over UDP Unicast) is sent to the +WINS server to obtain a lookup before DNS, HOSTS, LMHOSTS, or broadcast +lookup is used. +</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id425943"></a>WINS Lookup</h3></div></div></div><p> +<a class="indexterm" name="id425950"></a> +<a class="indexterm" name="id425957"></a> +<a class="indexterm" name="id425967"></a> +A WINS (Windows Internet Name Server) service is the equivalent of the +rfc1001/1002 specified NBNS (NetBIOS Name Server). A WINS server stores +the names and IP addresses that are registered by a Windows client +if the TCP/IP setup has been given at least one WINS server IP address. +</p><p> +To configure Samba to be a WINS server, the following parameter needs +to be added to the <code class="filename">smb.conf</code> file: +</p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id425996"></a><em class="parameter"><code>wins support = Yes</code></em></td></tr></table><p> +<a class="indexterm" name="id426011"></a> +To configure Samba to use a WINS server, the following parameters are +needed in the <code class="filename">smb.conf</code> file: +</p><table class="simplelist" border="0" summary="Simple list"><tr><td><a class="indexterm" name="id426032"></a><em class="parameter"><code>wins support = No</code></em></td></tr><tr><td><a class="indexterm" name="id426044"></a><em class="parameter"><code>wins server = xxx.xxx.xxx.xxx</code></em></td></tr></table><p> +where <em class="replaceable"><code>xxx.xxx.xxx.xxx</code></em> is the IP address +of the WINS server. +</p><p>For information about setting up Samba as a WINS server, read +<a href="NetworkBrowsing.html" title="Chapter 10. Network Browsing">Network Browsing</a>.</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id426077"></a>Common Errors</h2></div></div></div><p> +TCP/IP network configuration problems find every network administrator sooner or later. +The cause can be anything from keyboard mishaps to forgetfulness to simple mistakes to +carelessness. Of course, no one is ever deliberately careless! +</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id426088"></a>Pinging Works Only One Way</h3></div></div></div><p> + “<span class="quote">I can ping my Samba server from Windows, but I cannot ping my Windows + machine from the Samba server.</span>” + </p><p> + The Windows machine was at IP address 192.168.1.2 with netmask 255.255.255.0, the + Samba server (Linux) was at IP address 192.168.1.130 with netmask 255.255.255.128. + The machines were on a local network with no external connections. + </p><p> + Due to inconsistent netmasks, the Windows machine was on network 192.168.1.0/24, while + the Samba server was on network 192.168.1.128/25 logically a different network. + </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id426116"></a>Very Slow Network Connections</h3></div></div></div><p> + A common cause of slow network response includes: + </p><div class="itemizedlist"><ul type="disc"><li><p>Client is configured to use DNS and the DNS server is down.</p></li><li><p>Client is configured to use remote DNS server, but the + remote connection is down.</p></li><li><p>Client is configured to use a WINS server, but there is no WINS server.</p></li><li><p>Client is not configured to use a WINS server, but there is a WINS server.</p></li><li><p>Firewall is filtering out DNS or WINS traffic.</p></li></ul></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id426154"></a>Samba Server Name-Change Problem</h3></div></div></div><p> + “<span class="quote">The name of the Samba server was changed, Samba was restarted, and now the Samba server cannot be + pinged by its new name from an MS Windows NT4 workstation, but it does still respond to pinging using + the old name. Why?</span>” + </p><p> + From this description, three things are obvious: + </p><div class="itemizedlist"><ul type="disc"><li><p>WINS is not in use; only broadcast-based name resolution is used.</p></li><li><p>The Samba server was renamed and restarted within the last 10 or 15 minutes.</p></li><li><p>The old Samba server name is still in the NetBIOS name cache on the MS Windows NT4 workstation.</p></li></ul></div><p> + To find what names are present in the NetBIOS name cache on the MS Windows NT4 machine, + open a <code class="literal">cmd</code> shell and then: + </p><p> +</p><pre class="screen"> +<code class="prompt">C:\> </code><strong class="userinput"><code>nbtstat -n</code></strong> + + NetBIOS Local Name Table + + Name Type Status +------------------------------------------------ +FRODO <03> UNIQUE Registered +ADMINISTRATOR <03> UNIQUE Registered +FRODO <00> UNIQUE Registered +SARDON <00> GROUP Registered +FRODO <20> UNIQUE Registered +FRODO <1F> UNIQUE Registered + + +<code class="prompt">C:\> </code>nbtstat -c + + NetBIOS Remote Cache Name Table + + Name Type Host Address Life [sec] +-------------------------------------------------------------- +GANDALF <20> UNIQUE 192.168.1.1 240 + +<code class="prompt">C:\> </code> +</pre><p> + </p><p> + In this example, GANDALF is the Samba server and FRODO is the MS Windows NT4 workstation. + The first listing shows the contents of the Local Name Table (i.e., identity information on + the MS Windows workstation), and the second shows the NetBIOS name in the NetBIOS name cache. + The name cache contains the remote machines known to this workstation. + </p></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="pam.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="unicode.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 28. 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