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diff --git a/docs/htmldocs/winbind.html b/docs/htmldocs/winbind.html new file mode 100644 index 0000000000..480746898f --- /dev/null +++ b/docs/htmldocs/winbind.html @@ -0,0 +1,741 @@ +<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter 21. Winbind: Use of Domain Accounts</title><link rel="stylesheet" href="samba.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.60.1"><link rel="home" href="index.html" title="SAMBA Project Documentation"><link rel="up" href="optional.html" title="Part III. Advanced Configuration"><link rel="previous" href="VFS.html" title="Chapter 20. Stackable VFS modules"><link rel="next" href="AdvancedNetworkManagement.html" title="Chapter 22. Advanced Network Management"></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 21. Winbind: Use of Domain Accounts</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="VFS.html">Prev</a> </td><th width="60%" align="center">Part III. Advanced Configuration</th><td width="20%" align="right"> <a accesskey="n" href="AdvancedNetworkManagement.html">Next</a></td></tr></table><hr></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="winbind"></a>Chapter 21. Winbind: Use of Domain Accounts</h2></div><div><div class="author"><h3 class="author"><span class="firstname">Tim</span> <span class="surname">Potter</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><tt class="email"><<a href="mailto:tpot@linuxcare.com.au">tpot@linuxcare.com.au</a>></tt></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">Andrew</span> <span class="surname">Tridgell</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><tt class="email"><<a href="mailto:tridge@samba.org">tridge@samba.org</a>></tt></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">Naag</span> <span class="surname">Mummaneni</span></h3><span class="contrib">Notes for Solaris</span><div class="affiliation"><div class="address"><p><tt class="email"><<a href="mailto:getnag@rediffmail.com">getnag@rediffmail.com</a>></tt></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">John</span> <span class="surname">Trostel</span></h3><div class="affiliation"><div class="address"><p><tt class="email"><<a href="mailto:jtrostel@snapserver.com">jtrostel@snapserver.com</a>></tt></p></div><span class="orgname">SNAP<br></span></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><tt class="email"><<a href="mailto:jelmer@samba.org">jelmer@samba.org</a>></tt></p></div></div></div></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><tt class="email"><<a href="mailto:jht@samba.org">jht@samba.org</a>></tt></p></div></div></div></div><div><p class="pubdate">27 June 2002</p></div></div><div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><a href="winbind.html#id2949352">Features and Benefits</a></dt><dt><a href="winbind.html#id2949476">Introduction</a></dt><dt><a href="winbind.html#id2949558">What Winbind Provides</a></dt><dd><dl><dt><a href="winbind.html#id2949633">Target Uses</a></dt></dl></dd><dt><a href="winbind.html#id2949664">How Winbind Works</a></dt><dd><dl><dt><a href="winbind.html#id2949693">Microsoft Remote Procedure Calls</a></dt><dt><a href="winbind.html#id2949726">Microsoft Active Directory Services</a></dt><dt><a href="winbind.html#id2949752">Name Service Switch</a></dt><dt><a href="winbind.html#id2949887">Pluggable Authentication Modules</a></dt><dt><a href="winbind.html#id2949965">User and Group ID Allocation</a></dt><dt><a href="winbind.html#id2949998">Result Caching</a></dt></dl></dd><dt><a href="winbind.html#id2950035">Installation and Configuration</a></dt><dd><dl><dt><a href="winbind.html#id2950042">Introduction</a></dt><dt><a href="winbind.html#id2950108">Requirements</a></dt><dt><a href="winbind.html#id2950191">Testing Things Out</a></dt></dl></dd><dt><a href="winbind.html#id2951948">Conclusion</a></dt><dt><a href="winbind.html#id2951967">Common Errors</a></dt><dd><dl><dt><a href="winbind.html#id2952021">NSCD Problem Warning</a></dt><dt><a href="winbind.html#id2952067">Winbind Is Not Resolving Users and Groups</a></dt></dl></dd></dl></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2949352"></a>Features and Benefits</h2></div></div><div></div></div><p> + Integration of UNIX and Microsoft Windows NT through a unified logon has + been considered a “<span class="quote">holy grail</span>” in heterogeneous computing environments for + a long time. + </p><p> + There is one other facility without which UNIX and Microsoft Windows network + interoperability would suffer greatly. It is imperative that there be a + mechanism for sharing files across UNIX systems and to be able to assign + domain user and group ownerships with integrity. + </p><p> + <span class="emphasis"><em>winbind</em></span> is a component of the Samba suite of programs that + solves the unified logon problem. Winbind uses a UNIX implementation of Microsoft + RPC calls, Pluggable Authentication Modules, and the Name Service Switch to + allow Windows NT domain users to appear and operate as UNIX users on a UNIX + machine. This chapter describes the Winbind system, explaining the functionality + it provides, how it is configured, and how it works internally. + </p><p> + Winbind provides three separate functions: + </p><div class="itemizedlist"><ul type="disc"><li><p> + Authentication of user credentials (via PAM). + </p></li><li><p> + Identity resolution (via NSS). + </p></li><li><p> + Winbind maintains a database called winbind_idmap.tdb in which it stores + mappings between UNIX UIDs / GIDs and NT SIDs. This mapping is used only + for users and groups that do not have a local UID/GID. It stored the UID/GID + allocated from the idmap uid/gid range that it has mapped to the NT SID. + If <i class="parameter"><tt>idmap backend</tt></i> has been specified as ldapsam:url + then instead of using a local mapping Winbind will obtain this information + from the LDAP database. + </p></li></ul></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p> + If <b class="command">winbindd</b> is not running, smbd (which calls <b class="command">winbindd</b>) will fall back to + using purely local information from <tt class="filename">/etc/passwd</tt> and <tt class="filename">/etc/group</tt> and no dynamic + mapping will be used. + </p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2949476"></a>Introduction</h2></div></div><div></div></div><p>It is well known that UNIX and Microsoft Windows NT have + different models for representing user and group information and + use different technologies for implementing them. This fact has + made it difficult to integrate the two systems in a satisfactory + manner.</p><p>One common solution in use today has been to create + identically named user accounts on both the UNIX and Windows systems + and use the Samba suite of programs to provide file and print services + between the two. This solution is far from perfect, however, as + adding and deleting users on both sets of machines becomes a chore + and two sets of passwords are required both of which + can lead to synchronization problems between the UNIX and Windows + systems and confusion for users.</p><p>We divide the unified logon problem for UNIX machines into + three smaller problems:</p><div class="itemizedlist"><ul type="disc"><li><p>Obtaining Windows NT user and group information. + </p></li><li><p>Authenticating Windows NT users. + </p></li><li><p>Password changing for Windows NT users. + </p></li></ul></div><p>Ideally, a prospective solution to the unified logon problem + would satisfy all the above components without duplication of + information on the UNIX machines and without creating additional + tasks for the system administrator when maintaining users and + groups on either system. The Winbind system provides a simple + and elegant solution to all three components of the unified logon + problem.</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2949558"></a>What Winbind Provides</h2></div></div><div></div></div><p>Winbind unifies UNIX and Windows NT account management by + allowing a UNIX box to become a full member of an NT domain. Once + this is done the UNIX box will see NT users and groups as if + they were “<span class="quote">native</span>” UNIX users and groups, allowing the NT domain + to be used in much the same manner that NIS+ is used within + UNIX-only environments.</p><p>The end result is that whenever any + program on the UNIX machine asks the operating system to lookup + a user or group name, the query will be resolved by asking the + NT Domain Controller for the specified domain to do the lookup. + Because Winbind hooks into the operating system at a low level + (via the NSS name resolution modules in the C library), this + redirection to the NT Domain Controller is completely + transparent.</p><p>Users on the UNIX machine can then use NT user and group + names as they would “<span class="quote">native</span>” UNIX names. They can chown files + so they are owned by NT domain users or even login to the + UNIX machine and run a UNIX X-Window session as a domain user.</p><p>The only obvious indication that Winbind is being used is + that user and group names take the form <tt class="constant">DOMAIN\user</tt> and + <tt class="constant">DOMAIN\group</tt>. This is necessary as it allows Winbind to determine + that redirection to a Domain Controller is wanted for a particular + lookup and which trusted domain is being referenced.</p><p>Additionally, Winbind provides an authentication service + that hooks into the Pluggable Authentication Modules (PAM) system + to provide authentication via an NT domain to any PAM-enabled + applications. This capability solves the problem of synchronizing + passwords between systems since all passwords are stored in a single + location (on the Domain Controller).</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2949633"></a>Target Uses</h3></div></div><div></div></div><p>Winbind is targeted at organizations that have an + existing NT-based domain infrastructure into which they wish + to put UNIX workstations or servers. Winbind will allow these + organizations to deploy UNIX workstations without having to + maintain a separate account infrastructure. This greatly + simplifies the administrative overhead of deploying UNIX + workstations into an NT-based organization.</p><p>Another interesting way in which we expect Winbind to + be used is as a central part of UNIX-based appliances. Appliances + that provide file and print services to Microsoft-based networks + will be able to use Winbind to provide seamless integration of + the appliance into the domain.</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2949664"></a>How Winbind Works</h2></div></div><div></div></div><p>The Winbind system is designed around a client/server + architecture. A long running <b class="command">winbindd</b> daemon + listens on a UNIX domain socket waiting for requests + to arrive. These requests are generated by the NSS and PAM + clients and is processed sequentially.</p><p>The technologies used to implement Winbind are described + in detail below.</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2949693"></a>Microsoft Remote Procedure Calls</h3></div></div><div></div></div><p>Over the last few years, efforts have been underway + by various Samba Team members to decode various aspects of + the Microsoft Remote Procedure Call (MSRPC) system. This + system is used for most network-related operations between + Windows NT machines including remote management, user authentication + and print spooling. Although initially this work was done + to aid the implementation of Primary Domain Controller (PDC) + functionality in Samba, it has also yielded a body of code that + can be used for other purposes.</p><p>Winbind uses various MSRPC calls to enumerate domain users + and groups and to obtain detailed information about individual + users or groups. Other MSRPC calls can be used to authenticate + NT domain users and to change user passwords. By directly querying + a Windows PDC for user and group information, Winbind maps the + NT account information onto UNIX user and group names.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2949726"></a>Microsoft Active Directory Services</h3></div></div><div></div></div><p> + Since late 2001, Samba has gained the ability to + interact with Microsoft Windows 2000 using its “<span class="quote">Native + Mode</span>” protocols, rather than the NT4 RPC services. + Using LDAP and Kerberos, a Domain Member running + Winbind can enumerate users and groups in exactly the + same way as a Windows 200x client would, and in so doing + provide a much more efficient and effective Winbind implementation. + </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2949752"></a>Name Service Switch</h3></div></div><div></div></div><p>The Name Service Switch, or NSS, is a feature that is + present in many UNIX operating systems. It allows system + information such as hostnames, mail aliases and user information + to be resolved from different sources. For example, a standalone + UNIX workstation may resolve system information from a series of + flat files stored on the local filesystem. A networked workstation + may first attempt to resolve system information from local files, + and then consult an NIS database for user information or a DNS server + for hostname information.</p><p>The NSS application programming interface allows Winbind + to present itself as a source of system information when + resolving UNIX usernames and groups. Winbind uses this interface, + and information obtained from a Windows NT server using MSRPC + calls to provide a new source of account enumeration. Using standard + UNIX library calls, one can enumerate the users and groups on + a UNIX machine running Winbind and see all users and groups in + a NT domain plus any trusted domain as though they were local + users and groups.</p><p>The primary control file for NSS is + <tt class="filename">/etc/nsswitch.conf</tt>. + When a UNIX application makes a request to do a lookup, + the C library looks in <tt class="filename">/etc/nsswitch.conf</tt> + for a line that matches the service type being requested, for + example the “<span class="quote">passwd</span>” service type is used when user or group names + are looked up. This config line specifies which implementations + of that service should be tried and in what order. If the passwd + config line is:</p><pre class="screen"> + passwd: files example + </pre><p>then the C library will first load a module called + <tt class="filename">/lib/libnss_files.so</tt> followed by + the module <tt class="filename">/lib/libnss_example.so</tt>. The + C library will dynamically load each of these modules in turn + and call resolver functions within the modules to try to resolve + the request. Once the request is resolved, the C library returns the + result to the application.</p><p>This NSS interface provides an easy way for Winbind + to hook into the operating system. All that needs to be done + is to put <tt class="filename">libnss_winbind.so</tt> in <tt class="filename">/lib/</tt> + then add “<span class="quote">winbind</span>” into <tt class="filename">/etc/nsswitch.conf</tt> at + the appropriate place. The C library will then call Winbind to + resolve user and group names.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2949887"></a>Pluggable Authentication Modules</h3></div></div><div></div></div><p>Pluggable Authentication Modules, also known as PAM, + is a system for abstracting authentication and authorization + technologies. With a PAM module it is possible to specify different + authentication methods for different system applications without + having to recompile these applications. PAM is also useful + for implementing a particular policy for authorization. For example, + a system administrator may only allow console logins from users + stored in the local password file but only allow users resolved from + a NIS database to log in over the network.</p><p>Winbind uses the authentication management and password + management PAM interface to integrate Windows NT users into a + UNIX system. This allows Windows NT users to log in to a UNIX + machine and be authenticated against a suitable Primary Domain + Controller. These users can also change their passwords and have + this change take effect directly on the Primary Domain Controller. + </p><p>PAM is configured by providing control files in the directory + <tt class="filename">/etc/pam.d/</tt> for each of the services that + require authentication. When an authentication request is made + by an application, the PAM code in the C library looks up this + control file to determine what modules to load to do the + authentication check and in what order. This interface makes adding + a new authentication service for Winbind very easy. All that needs + to be done is that the <tt class="filename">pam_winbind.so</tt> module + is copied to <tt class="filename">/lib/security/</tt> and the PAM + control files for relevant services are updated to allow + authentication via Winbind. See the PAM documentation + in <link linkend="pam"> for more information.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2949965"></a>User and Group ID Allocation</h3></div></div><div></div></div><p>When a user or group is created under Windows NT/200x + it is allocated a numerical relative identifier (RID). This is + slightly different from UNIX which has a range of numbers that are + used to identify users, and the same range in which to identify + groups. It is Winbind's job to convert RIDs to UNIX ID numbers and + vice versa. When Winbind is configured, it is given part of the UNIX + user ID space and a part of the UNIX group ID space in which to + store Windows NT users and groups. If a Windows NT user is + resolved for the first time, it is allocated the next UNIX ID from + the range. The same process applies for Windows NT groups. Over + time, Winbind will have mapped all Windows NT users and groups + to UNIX user IDs and group IDs.</p><p>The results of this mapping are stored persistently in + an ID mapping database held in a tdb database). This ensures that + RIDs are mapped to UNIX IDs in a consistent way.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2949998"></a>Result Caching</h3></div></div><div></div></div><p> +<a class="indexterm" name="id2950010"></a> + An active system can generate a lot of user and group + name lookups. To reduce the network cost of these lookups, Winbind + uses a caching scheme based on the SAM sequence number supplied + by NT Domain Controllers. User or group information returned + by a PDC is cached by Winbind along with a sequence number also + returned by the PDC. This sequence number is incremented by + Windows NT whenever any user or group information is modified. If + a cached entry has expired, the sequence number is requested from + the PDC and compared against the sequence number of the cached entry. + If the sequence numbers do not match, then the cached information + is discarded and up-to-date information is requested directly + from the PDC.</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2950035"></a>Installation and Configuration</h2></div></div><div></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2950042"></a>Introduction</h3></div></div><div></div></div><p> +This section describes the procedures used to get Winbind up and +running. Winbind is capable of providing access +and authentication control for Windows Domain users through an NT +or Windows 200x PDC for regular services, such as telnet and ftp, as +well for Samba services. +</p><div class="itemizedlist"><ul type="disc"><li><p> + <span class="emphasis"><em>Why should I do this?</em></span> + </p><p>This allows the Samba administrator to rely on the + authentication mechanisms on the Windows NT/200x PDC for the authentication + of Domain Members. Windows NT/200x users no longer need to have separate + accounts on the Samba server. + </p></li><li><p> + <span class="emphasis"><em>Who should be reading this document?</em></span> + </p><p> + This document is designed for system administrators. If you are + implementing Samba on a file server and wish to (fairly easily) + integrate existing Windows NT/200x users from your PDC onto the + Samba server, this document is for you. + </p></li></ul></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2950108"></a>Requirements</h3></div></div><div></div></div><p> +If you have a Samba configuration file that you are currently using, <span class="emphasis"><em>BACK IT UP!</em></span> +If your system already uses PAM, <span class="emphasis"><em>back up the <tt class="filename">/etc/pam.d</tt> directory +contents!</em></span> If you haven't already made a boot disk, <span class="emphasis"><em>MAKE ONE NOW!</em></span> +</p><p> +Messing with the PAM configuration files can make it nearly impossible to log in to your machine. That's +why you want to be able to boot back into your machine in single user mode and restore your +<tt class="filename">/etc/pam.d</tt> back to the original state they were in if you get frustrated with the +way things are going. +</p><p> +The latest version of Samba-3 includes a functioning winbindd daemon. Please refer to the <ulink url="http://samba.org/">main Samba Web page</ulink> or, better yet, your closest Samba mirror site for +instructions on downloading the source code. +</p><p> +To allow domain users the ability to access Samba shares and files, as well as potentially other services +provided by your Samba machine, PAM must be set up properly on your +machine. In order to compile the Winbind modules, you should have at least the PAM development libraries installed +on your system. Please refer the PAM web site <ulink url="http://www.kernel.org/pub/linux/libs/pam/">http://www.kernel.org/pub/linux/libs/pam/</ulink>. +</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2950191"></a>Testing Things Out</h3></div></div><div></div></div><p> +Before starting, it is probably best to kill off all the Samba-related daemons running on your server. +Kill off all <span class="application">smbd</span>, <span class="application">nmbd</span>, and <span class="application">winbindd</span> processes that may be running. To use PAM, +make sure that you have the standard PAM package that supplies the <tt class="filename">/etc/pam.d</tt> +directory structure, including the PAM modules that are used by PAM-aware services, several pam libraries, +and the <tt class="filename">/usr/doc</tt> and <tt class="filename">/usr/man</tt> entries for pam. Winbind built +better in Samba if the pam-devel package is also installed. This package includes the header files +needed to compile PAM-aware applications. +</p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2950252"></a>Configure <tt class="filename">nsswitch.conf</tt> and the Winbind Libraries on Linux and Solaris</h4></div></div><div></div></div><p> +PAM is a standard component of most current generation UNIX/Linux systems. Unfortunately, few systems install +the <tt class="filename">pam-devel</tt> libraries that are needed to build PAM-enabled Samba. Additionally, Samba-3 +may auto-install the Winbind files into their correct locations on your system, so before you get too far down +the track be sure to check if the following configuration is really +necessary. You may only need to configure +<tt class="filename">/etc/nsswitch.conf</tt>. +</p><p> +The libraries needed to run the <span class="application">winbindd</span> daemon through nsswitch need to be copied to their proper locations: +</p><p> +</p><pre class="screen"> +<tt class="prompt">root# </tt><b class="userinput"><tt>cp ../samba/source/nsswitch/libnss_winbind.so /lib</tt></b> +</pre><p> +</p><p> +I also found it necessary to make the following symbolic link: +</p><p> +<tt class="prompt">root# </tt> <b class="userinput"><tt>ln -s /lib/libnss_winbind.so /lib/libnss_winbind.so.2</tt></b> +</p><p>And, in the case of Sun Solaris:</p><pre class="screen"> +<tt class="prompt">root# </tt><b class="userinput"><tt>ln -s /usr/lib/libnss_winbind.so /usr/lib/libnss_winbind.so.1</tt></b> +<tt class="prompt">root# </tt><b class="userinput"><tt>ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.1</tt></b> +<tt class="prompt">root# </tt><b class="userinput"><tt>ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.2</tt></b> +</pre><p> +Now, as root you need to edit <tt class="filename">/etc/nsswitch.conf</tt> to +allow user and group entries to be visible from the <span class="application">winbindd</span> +daemon. My <tt class="filename">/etc/nsswitch.conf</tt> file look like +this after editing: +</p><pre class="programlisting"> + passwd: files winbind + shadow: files + group: files winbind +</pre><p> +The libraries needed by the <b class="command">winbindd</b> daemon will be automatically +entered into the <b class="command">ldconfig</b> cache the next time +your system reboots, but it is faster (and you do not need to reboot) if you do it manually: +</p><p> +<tt class="prompt">root# </tt><b class="userinput"><tt>/sbin/ldconfig -v | grep winbind</tt></b> +</p><p> +This makes <tt class="filename">libnss_winbind</tt> available to winbindd +and echos back a check to you. +</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2950492"></a>NSS Winbind on AIX</h4></div></div><div></div></div><p>(This section is only for those running AIX.)</p><p> +The Winbind AIX identification module gets built as <tt class="filename">libnss_winbind.so</tt> in the +nsswitch directory of the Samba source. This file can be copied to <tt class="filename">/usr/lib/security</tt>, +and the AIX naming convention would indicate that it should be named WINBIND. A stanza like the following: +</p><pre class="programlisting"> +WINBIND: + program = /usr/lib/security/WINBIND + options = authonly +</pre><p> +can then be added to <tt class="filename">/usr/lib/security/methods.cfg</tt>. This module only supports +identification, but there have been success reports using the standard Winbind PAM module for +authentication. Use caution configuring loadable authentication +modules since you can make +it impossible to logon to the system. More information about the AIX authentication module API can +be found at “<span class="quote">Kernel Extensions and Device Support Programming Concepts for AIX</span>”<ulink url="http://publibn.boulder.ibm.com/doc_link/en_US/a_doc_lib/aixprggd/kernextc/sec_load_mod.htm"> +in Chapter 18(John, there is no section like this in 18). Loadable Authentication Module Programming +Interface</ulink> and more information on administering the modules +can be found at <ulink url="http://publibn.boulder.ibm.com/doc_link/en_US/a_doc_lib/aixbman/baseadmn/iandaadmin.htm"> System +Management Guide: Operating System and Devices.</ulink> +</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2950584"></a>Configure smb.conf</h4></div></div><div></div></div><p> +Several parameters are needed in the <tt class="filename">smb.conf</tt> file to control the behavior of <span class="application">winbindd</span>. These +are described in more detail in the <a href="winbindd.8.html"><span class="citerefentry"><span class="refentrytitle">winbindd</span>(8)</span></a> man page. My <tt class="filename">smb.conf</tt> file, as shown in <link linkend="winbindcfg">, was modified to include the necessary entries in the [global] section. +</p><div class="example"><a name="winbindcfg"></a><p class="title"><b>Example 21.1. smb.conf for Winbind set-up</b></p><table class="simplelist" border="0" summary="Simple list"><tr><td> </td></tr><tr><td><i class="parameter"><tt>[global]</tt></i></td></tr><tr><td># separate domain and username with '+', like DOMAIN+username</td></tr><tr><td><i class="parameter"><tt>winbind separator = +</tt></i></td></tr><tr><td># use uids from 10000 to 20000 for domain users</td></tr><tr><td><i class="parameter"><tt>idmap uid = 10000-20000</tt></i></td></tr><tr><td># use gids from 10000 to 20000 for domain groups</td></tr><tr><td><i class="parameter"><tt>winbind gid = 10000-20000</tt></i></td></tr><tr><td># allow enumeration of winbind users and groups</td></tr><tr><td><i class="parameter"><tt>winbind enum users = yes</tt></i></td></tr><tr><td><i class="parameter"><tt>winbind enum groups = yes</tt></i></td></tr><tr><td># give winbind users a real shell (only needed if they have telnet access)</td></tr><tr><td><i class="parameter"><tt>template homedir = /home/winnt/%D/%U</tt></i></td></tr><tr><td><i class="parameter"><tt>template shell = /bin/bash</tt></i></td></tr></table></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2950748"></a>Join the Samba Server to the PDC Domain</h4></div></div><div></div></div><p> +Enter the following command to make the Samba server join the +PDC domain, where <i class="replaceable"><tt>DOMAIN</tt></i> is the name of +your Windows domain and <i class="replaceable"><tt>Administrator</tt></i> is +a domain user who has administrative privileges in the domain. +</p><p> +<tt class="prompt">root# </tt><b class="userinput"><tt>/usr/local/samba/bin/net rpc join -S PDC -U Administrator</tt></b> +</p><p> +The proper response to the command should be: “<span class="quote">Joined the domain +<i class="replaceable"><tt>DOMAIN</tt></i></span>” where <i class="replaceable"><tt>DOMAIN</tt></i> +is your DOMAIN name. +</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2950807"></a>Starting and Testing the <b class="command">winbindd</b> Daemon</h4></div></div><div></div></div><p> +Eventually, you will want to modify your Samba startup script to +automatically invoke the winbindd daemon when the other parts of +Samba start, but it is possible to test out just the Winbind +portion first. To start up Winbind services, enter the following +command as root: +</p><p> +<tt class="prompt">root# </tt><b class="userinput"><tt>/usr/local/samba/bin/winbindd</tt></b> +</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p> +The above assumes that Samba has been installed in the <tt class="filename">/usr/local/samba</tt> +directory tree. You may need to search for the location of Samba files if this is not the +location of <b class="command">winbindd</b> on your system. +</p></div><p> +Winbindd can now also run in “<span class="quote">dual daemon modei</span>”. This will make it +run as two processes. The first will answer all requests from the cache, +thus making responses to clients faster. The other will +update the cache for the query that the first has just responded. +The advantage of this is that responses stay accurate and are faster. +You can enable dual daemon mode by adding <tt class="option">-B</tt> to the commandline: +</p><p> +<tt class="prompt">root# </tt><b class="userinput"><tt>/usr/local/samba/bin/winbindd -B</tt></b> +</p><p> +I'm always paranoid and like to make sure the daemon is really running. +</p><p> +<tt class="prompt">root# </tt><b class="userinput"><tt>ps -ae | grep winbindd</tt></b> +</p><p> +This command should produce output like this, if the daemon is running you would expect +to see a report something like this: +</p><pre class="screen"> +3025 ? 00:00:00 winbindd +</pre><p> +Now, for the real test, try to get some information about the users on your PDC: +</p><p> +<tt class="prompt">root# </tt><b class="userinput"><tt>/usr/local/samba/bin/wbinfo -u</tt></b> +</p><p> +This should echo back a list of users on your Windows users on +your PDC. For example, I get the following response: +</p><pre class="screen"> + CEO+Administrator + CEO+burdell + CEO+Guest + CEO+jt-ad + CEO+krbtgt + CEO+TsInternetUser +</pre><p> +Obviously, I have named my domain “<span class="quote">CEO</span>” and my <a class="indexterm" name="id2950988"></a><i class="parameter"><tt>winbind separator</tt></i> is “<span class="quote">+</span>”. +</p><p> +You can do the same sort of thing to get group information from the PDC: +</p><pre class="screen"> +<tt class="prompt">root# </tt><b class="userinput"><tt>/usr/local/samba/bin/wbinfo -g</tt></b> + CEO+Domain Admins + CEO+Domain Users + CEO+Domain Guests + CEO+Domain Computers + CEO+Domain Controllers + CEO+Cert Publishers + CEO+Schema Admins + CEO+Enterprise Admins + CEO+Group Policy Creator Owners +</pre><p> +The function <b class="command">getent</b> can now be used to get unified +lists of both local and PDC users and groups. Try the following command: +</p><p> +<tt class="prompt">root# </tt><b class="userinput"><tt>getent passwd</tt></b> +</p><p> +You should get a list that looks like your <tt class="filename">/etc/passwd</tt> +list followed by the domain users with their new UIDs, GIDs, home +directories and default shells. +</p><p> +The same thing can be done for groups with the command: +</p><p> +<tt class="prompt">root# </tt><b class="userinput"><tt>getent group</tt></b> +</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2951103"></a>Fix the init.d Startup Scripts</h4></div></div><div></div></div><div class="sect4" lang="en"><div class="titlepage"><div><div><h5 class="title"><a name="id2951110"></a>Linux</h5></div></div><div></div></div><p> +The <span class="application">winbindd</span> daemon needs to start up after the <span class="application">smbd</span> and <span class="application">nmbd</span> daemons are running. +To accomplish this task, you need to modify the startup scripts of your system. +They are located at <tt class="filename">/etc/init.d/smb</tt> in Red Hat Linux and they are located in +<tt class="filename">/etc/init.d/samba</tt> in Debian Linux. Edit your +script to add commands to invoke this daemon in the proper sequence. My +startup script starts up <span class="application">smbd</span>, <span class="application">nmbd</span>, and <span class="application">winbindd</span> from the +<tt class="filename">/usr/local/samba/bin</tt> directory directly. The <b class="command">start</b> +function in the script looks like this: +</p><pre class="programlisting"> +start() { + KIND="SMB" + echo -n $"Starting $KIND services: " + daemon /usr/local/samba/bin/smbd $SMBDOPTIONS + RETVAL=$? + echo + KIND="NMB" + echo -n $"Starting $KIND services: " + daemon /usr/local/samba/bin/nmbd $NMBDOPTIONS + RETVAL2=$? + echo + KIND="Winbind" + echo -n $"Starting $KIND services: " + daemon /usr/local/samba/bin/winbindd + RETVAL3=$? + echo + [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] && \ + touch /var/lock/subsys/smb || RETVAL=1 + return $RETVAL +} +</pre><p>If you would like to run winbindd in dual daemon mode, replace +the line : +</p><pre class="programlisting"> + daemon /usr/local/samba/bin/winbindd +</pre><p> + +in the example above with: + +</p><pre class="programlisting"> + daemon /usr/local/samba/bin/winbindd -B +</pre><p>. +</p><p> +The <b class="command">stop</b> function has a corresponding entry to shut down the +services and looks like this: +</p><pre class="programlisting"> +stop() { + KIND="SMB" + echo -n $"Shutting down $KIND services: " + killproc smbd + RETVAL=$? + echo + KIND="NMB" + echo -n $"Shutting down $KIND services: " + killproc nmbd + RETVAL2=$? + echo + KIND="Winbind" + echo -n $"Shutting down $KIND services: " + killproc winbindd + RETVAL3=$? + [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] && \ + rm -f /var/lock/subsys/smb + echo "" + return $RETVAL +} +</pre></div><div class="sect4" lang="en"><div class="titlepage"><div><div><h5 class="title"><a name="id2951286"></a>Solaris</h5></div></div><div></div></div><p> +Winbind does not work on Solaris 9, see <link linkend="winbind-solaris9"> for details. +</p><p> +On Solaris, you need to modify the <tt class="filename">/etc/init.d/samba.server</tt> startup script. It +usually only starts smbd and nmbd but should now start winbindd, too. If you have Samba installed in +<tt class="filename">/usr/local/samba/bin</tt>, the file could contains something like this: +</p><pre class="programlisting"> + ## + ## samba.server + ## + + if [ ! -d /usr/bin ] + then # /usr not mounted + exit + fi + + killproc() { # kill the named process(es) + pid=`/usr/bin/ps -e | + /usr/bin/grep -w $1 | + /usr/bin/sed -e 's/^ *//' -e 's/ .*//'` + [ "$pid" != "" ] && kill $pid + } + + # Start/stop processes required for Samba server + + case "$1" in + + 'start') + # + # Edit these lines to suit your installation (paths, workgroup, host) + # + echo Starting SMBD + /usr/local/samba/bin/smbd -D -s \ + /usr/local/samba/smb.conf + + echo Starting NMBD + /usr/local/samba/bin/nmbd -D -l \ + /usr/local/samba/var/log -s /usr/local/samba/smb.conf + + echo Starting Winbind Daemon + /usr/local/samba/bin/winbindd + ;; + + 'stop') + killproc nmbd + killproc smbd + killproc winbindd + ;; + + *) + echo "Usage: /etc/init.d/samba.server { start | stop }" + ;; + esac +</pre><p> +Again, if you would like to run Samba in dual daemon mode, replace: +</p><pre class="programlisting"> + /usr/local/samba/bin/winbindd +</pre><p> +in the script above with: +</p><pre class="programlisting"> + /usr/local/samba/bin/winbindd -B +</pre><p> +</p></div><div class="sect4" lang="en"><div class="titlepage"><div><div><h5 class="title"><a name="id2951403"></a>Restarting</h5></div></div><div></div></div><p> +If you restart the <span class="application">smbd</span>, <span class="application">nmbd</span>, and <span class="application">winbindd</span> daemons at this point, you +should be able to connect to the Samba server as a Domain Member just as +if you were a local user. +</p></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2951439"></a>Configure Winbind and PAM</h4></div></div><div></div></div><p> +If you have made it this far, you know that <b class="command">winbindd</b> and Samba are working +together. If you want to use Winbind to provide authentication for other +services, keep reading. The PAM configuration files need to be altered in +this step. (Did you remember to make backups of your original +<tt class="filename">/etc/pam.d</tt> files? If not, do it now.) +</p><p> +You will need a PAM module to use winbindd with these other services. This +module will be compiled in the <tt class="filename">../source/nsswitch</tt> directory +by invoking the command: +</p><p> +<tt class="prompt">root# </tt><b class="userinput"><tt>make nsswitch/pam_winbind.so</tt></b> +</p><p> +from the <tt class="filename">../source</tt> directory. The +<tt class="filename">pam_winbind.so</tt> file should be copied to the location of +your other PAM security modules. On my RedHat system, this was the +<tt class="filename">/lib/security</tt> directory. On Solaris, the PAM security +modules reside in <tt class="filename">/usr/lib/security</tt>. +</p><p> +<tt class="prompt">root# </tt><b class="userinput"><tt>cp ../samba/source/nsswitch/pam_winbind.so /lib/security</tt></b> +</p><div class="sect4" lang="en"><div class="titlepage"><div><div><h5 class="title"><a name="id2951551"></a>Linux/FreeBSD-specific PAM configuration</h5></div></div><div></div></div><p> +The <tt class="filename">/etc/pam.d/samba</tt> file does not need to be changed. I +just left this file as it was: +</p><pre class="programlisting"> + auth required /lib/security/pam_stack.so service=system-auth + account required /lib/security/pam_stack.so service=system-auth +</pre><p> +The other services that I modified to allow the use of Winbind +as an authentication service were the normal login on the console (or a terminal +session), telnet logins, and ftp service. In order to enable these +services, you may first need to change the entries in +<tt class="filename">/etc/xinetd.d</tt> (or <tt class="filename">/etc/inetd.conf</tt>). +Red Hat Linux 7.1 and later uses the new xinetd.d structure, in this case you need +to change the lines in <tt class="filename">/etc/xinetd.d/telnet</tt> +and <tt class="filename">/etc/xinetd.d/wu-ftp</tt> from +</p><pre class="programlisting"> + enable = no +</pre><p> +to: +</p><pre class="programlisting"> + enable = yes +</pre><p> +For ftp services to work properly, you will also need to either +have individual directories for the domain users already present on +the server, or change the home directory template to a general +directory for all domain users. These can be easily set using +the <tt class="filename">smb.conf</tt> global entry +<a class="indexterm" name="id2951653"></a><i class="parameter"><tt>template homedir</tt></i>. +</p><p> +The <tt class="filename">/etc/pam.d/ftp</tt> file can be changed +to allow Winbind ftp access in a manner similar to the +samba file. My <tt class="filename">/etc/pam.d/ftp</tt> file was +changed to look like this: +</p><pre class="programlisting"> +auth required /lib/security/pam_listfile.so item=user sense=deny \ + file=/etc/ftpusers onerr=succeed +auth sufficient /lib/security/pam_winbind.so +auth required /lib/security/pam_stack.so service=system-auth +auth required /lib/security/pam_shells.so +account sufficient /lib/security/pam_winbind.so +account required /lib/security/pam_stack.so service=system-auth +session required /lib/security/pam_stack.so service=system-auth +</pre><p> +The <tt class="filename">/etc/pam.d/login</tt> file can be changed nearly the +same way. It now looks like this: +</p><pre class="programlisting"> +auth required /lib/security/pam_securetty.so +auth sufficient /lib/security/pam_winbind.so +auth sufficient /lib/security/pam_UNIX.so use_first_pass +auth required /lib/security/pam_stack.so service=system-auth +auth required /lib/security/pam_nologin.so +account sufficient /lib/security/pam_winbind.so +account required /lib/security/pam_stack.so service=system-auth +password required /lib/security/pam_stack.so service=system-auth +session required /lib/security/pam_stack.so service=system-auth +session optional /lib/security/pam_console.so +</pre><p> +In this case, I added the </p><pre class="programlisting">auth sufficient /lib/security/pam_winbind.so</pre><p> +lines as before, but also added the </p><pre class="programlisting">required pam_securetty.so</pre><p> +above it, to disallow root logins over the network. I also added a +</p><pre class="programlisting">sufficient /lib/security/pam_unix.so use_first_pass</pre><p> +line after the <b class="command">winbind.so</b> line to get rid of annoying +double prompts for passwords. +</p></div><div class="sect4" lang="en"><div class="titlepage"><div><div><h5 class="title"><a name="id2951787"></a>Solaris-specific configuration</h5></div></div><div></div></div><p> +The <tt class="filename">/etc/pam.conf</tt> needs to be changed. I changed this file so my Domain +users can logon both locally as well as telnet. The following are the changes +that I made. You can customize the <tt class="filename">pam.conf</tt> file as per your requirements, but +be sure of those changes because in the worst case it will leave your system +nearly impossible to boot. +</p><pre class="programlisting"> +# +#ident "@(#)pam.conf 1.14 99/09/16 SMI" +# +# Copyright (c) 1996-1999, Sun Microsystems, Inc. +# All Rights Reserved. +# +# PAM configuration +# +# Authentication management +# +login auth required /usr/lib/security/pam_winbind.so +login auth required /usr/lib/security/$ISA/pam_UNIX.so.1 try_first_pass +login auth required /usr/lib/security/$ISA/pam_dial_auth.so.1 try_first_pass +# +rlogin auth sufficient /usr/lib/security/pam_winbind.so +rlogin auth sufficient /usr/lib/security/$ISA/pam_rhosts_auth.so.1 +rlogin auth required /usr/lib/security/$ISA/pam_UNIX.so.1 try_first_pass +# +dtlogin auth sufficient /usr/lib/security/pam_winbind.so +dtlogin auth required /usr/lib/security/$ISA/pam_UNIX.so.1 try_first_pass +# +rsh auth required /usr/lib/security/$ISA/pam_rhosts_auth.so.1 +other auth sufficient /usr/lib/security/pam_winbind.so +other auth required /usr/lib/security/$ISA/pam_UNIX.so.1 try_first_pass +# +# Account management +# +login account sufficient /usr/lib/security/pam_winbind.so +login account requisite /usr/lib/security/$ISA/pam_roles.so.1 +login account required /usr/lib/security/$ISA/pam_UNIX.so.1 +# +dtlogin account sufficient /usr/lib/security/pam_winbind.so +dtlogin account requisite /usr/lib/security/$ISA/pam_roles.so.1 +dtlogin account required /usr/lib/security/$ISA/pam_UNIX.so.1 +# +other account sufficient /usr/lib/security/pam_winbind.so +other account requisite /usr/lib/security/$ISA/pam_roles.so.1 +other account required /usr/lib/security/$ISA/pam_UNIX.so.1 +# +# Session management +# +other session required /usr/lib/security/$ISA/pam_UNIX.so.1 +# +# Password management +# +#other password sufficient /usr/lib/security/pam_winbind.so +other password required /usr/lib/security/$ISA/pam_UNIX.so.1 +dtsession auth required /usr/lib/security/$ISA/pam_UNIX.so.1 +# +# Support for Kerberos V5 authentication (uncomment to use Kerberos) +# +#rlogin auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass +#login auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass +#dtlogin auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass +#other auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass +#dtlogin account optional /usr/lib/security/$ISA/pam_krb5.so.1 +#other account optional /usr/lib/security/$ISA/pam_krb5.so.1 +#other session optional /usr/lib/security/$ISA/pam_krb5.so.1 +#other password optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass +</pre><p> +I also added a <i class="parameter"><tt>try_first_pass</tt></i> line after the <tt class="filename">winbind.so</tt> +line to get rid of annoying double prompts for passwords. +</p><p> +Now restart your Samba and try connecting through your application that you +configured in the pam.conf. +</p></div></div></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2951948"></a>Conclusion</h2></div></div><div></div></div><p>The Winbind system, through the use of the Name Service +Switch, Pluggable Authentication Modules, and appropriate +Microsoft RPC calls have allowed us to provide seamless +integration of Microsoft Windows NT domain users on a +UNIX system. The result is a great reduction in the administrative +cost of running a mixed UNIX and NT network.</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2951967"></a>Common Errors</h2></div></div><div></div></div><p>Winbind has a number of limitations in its current + released version that we hope to overcome in future + releases:</p><div class="itemizedlist"><ul type="disc"><li><p>Winbind is currently only available for + the Linux, Solaris, AIX, and IRIX operating systems, although ports to other operating + systems are certainly possible. For such ports to be feasible, + we require the C library of the target operating system to + support the Name Service Switch and Pluggable Authentication + Modules systems. This is becoming more common as NSS and + PAM gain support among UNIX vendors.</p></li><li><p>The mappings of Windows NT RIDs to UNIX IDs + is not made algorithmically and depends on the order in which + unmapped users or groups are seen by Winbind. It may be difficult + to recover the mappings of RID to UNIX ID mapping if the file + containing this information is corrupted or destroyed.</p></li><li><p>Currently the Winbind PAM module does not take + into account possible workstation and logon time restrictions + that may be set for Windows NT users, this is + instead up to the PDC to enforce.</p></li></ul></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2952021"></a>NSCD Problem Warning</h3></div></div><div></div></div><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p> + Do not under any circumstances run <b class="command">nscd</b> on any system + on which <b class="command">winbindd</b> is running. + </p></div><p> + If <b class="command">nscd</b> is running on the UNIX/Linux system, then + even though NSSWITCH is correctly configured it will not be possible to resolve + domain users and groups for file and directory controls. + </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2952067"></a>Winbind Is Not Resolving Users and Groups</h3></div></div><div></div></div><p>“<span class="quote"> + My <tt class="filename">smb.conf</tt> file is correctly configured. I have specified + <a class="indexterm" name="id2952087"></a><i class="parameter"><tt>idmap uid</tt></i> = 12000, + and <a class="indexterm" name="id2952101"></a><i class="parameter"><tt>idmap gid</tt></i> = 3000-3500 + and <b class="command">winbind</b> is running. When I do the following it all works fine. + </span>”</p><pre class="screen"> +<tt class="prompt">root# </tt><b class="userinput"><tt>wbinfo -u</tt></b> +MIDEARTH+maryo +MIDEARTH+jackb +MIDEARTH+ameds +... +MIDEARTH+root + +<tt class="prompt">root# </tt><b class="userinput"><tt>wbinfo -g</tt></b> +MIDEARTH+Domain Users +MIDEARTH+Domain Admins +MIDEARTH+Domain Guests +... +MIDEARTH+Accounts + +<tt class="prompt">root# </tt><b class="userinput"><tt>getent passwd</tt></b> +root:x:0:0:root:/root:/bin/bash +bin:x:1:1:bin:/bin:/bin/bash +... +maryo:x:15000:15003:Mary Orville:/home/MIDEARTH/maryo:/bin/false +</pre><p>“<span class="quote"> +But the following command just fails: +<pre class="screen"> +<tt class="prompt">root# </tt><b class="userinput"><tt>chown maryo a_file</tt></b> +chown: `maryo': invalid user +</pre> +This is driving me nuts! What can be wrong? +</span>”</p><p> +Same problem as the one above. +Your system is likely running <b class="command">nscd</b>, the name service +caching daemon. Shut it down, do not restart it! You will find your problem resolved. +</p></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="VFS.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="AdvancedNetworkManagement.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 20. Stackable VFS modules </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 22. Advanced Network Management</td></tr></table></div></body></html> |