source: branches/samba-3.5.x/docs-xml/smbdotconf/security/passwordserver.xml

<samba:parameter name="password server"
                 context="G"
                                 type="list"
                 advanced="1" wizard="1" developer="1"
                 xmlns:samba="http://www.samba.org/samba/DTD/samba-doc">
<description>
    <para>By specifying the name of another SMB server 
    or Active Directory domain controller with this option, 
    and using <command moreinfo="none">security = [ads|domain|server]</command> 
    it is possible to get Samba
    to do all its username/password validation using a specific remote server.</para>

    <para>This option sets the name or IP address of the password server to use. 
    New syntax has been added to support defining the port to use when connecting 
    to the server the case of an ADS realm.  To define a port other than the
    default LDAP port of 389, add the port number using a colon after the 
    name or IP address (e.g. 192.168.1.100:389).  If you do not specify a port,
    Samba will use the standard LDAP port of tcp/389.  Note that port numbers
    have no effect on password servers for Windows NT 4.0 domains or netbios 
    connections.</para>

    <para>If parameter is a name, it is looked up using the 
    parameter <smbconfoption name="name resolve order"/> and so may resolved
    by any method and order described in that parameter.</para>

    <para>The password server must be a machine capable of using 
    the &quot;LM1.2X002&quot; or the &quot;NT LM 0.12&quot; protocol, and it must be in 
    user level security mode.</para>

    <note><para>Using a password server  means your UNIX box (running
    Samba) is only as secure as your  password server. <emphasis>DO NOT
    CHOOSE A PASSWORD SERVER THAT  YOU DON'T COMPLETELY TRUST</emphasis>.
    </para></note>
                
    <para>Never point a Samba server at itself for password serving.
    This will cause a loop and could lock up your Samba  server!</para>

    <para>The name of the password server takes the standard 
    substitutions, but probably the only useful one is <parameter moreinfo="none">%m
    </parameter>, which means the Samba server will use the incoming 
    client as the password server. If you use this then you better 
    trust your clients, and you had better restrict them with hosts allow!</para>

    <para>If the <parameter moreinfo="none">security</parameter> parameter is set to
    <constant>domain</constant> or <constant>ads</constant>, then the list of machines in this 
    option must be a list of Primary or Backup Domain controllers for the
    Domain or the character '*', as the Samba server is effectively
    in that domain, and will use cryptographically authenticated RPC calls
    to authenticate the user logging on. The advantage of using <command moreinfo="none">
    security = domain</command> is that if you list several hosts in the 
    <parameter moreinfo="none">password server</parameter> option then <command moreinfo="none">smbd
    </command> will try each in turn till it finds one that responds.  This
    is useful in case your primary server goes down.</para>

    <para>If the <parameter moreinfo="none">password server</parameter> option is set 
    to the character '*', then Samba will attempt to auto-locate the 
    Primary or Backup Domain controllers to authenticate against by 
    doing a query for the name <constant>WORKGROUP&lt;1C&gt;</constant> 
    and then contacting each server returned in the list of IP 
    addresses from the name resolution source. </para>

    <para>If the list of servers contains both names/IP's and the '*'
    character, the list is treated as a list of preferred 
    domain controllers, but an auto lookup of all remaining DC's
    will be added to the list as well.  Samba will not attempt to optimize 
    this list by locating the closest DC.</para>
                
    <para>If the <parameter moreinfo="none">security</parameter> parameter is 
    set to <constant>server</constant>, then there are different
    restrictions that <command moreinfo="none">security = domain</command> doesn't 
    suffer from:</para>

    <itemizedlist>
        <listitem>
            <para>You may list several password servers in 
            the <parameter moreinfo="none">password server</parameter> parameter, however if an 
            <command moreinfo="none">smbd</command> makes a connection to a password server, 
            and then the password server fails, no more users will be able 
            to be authenticated from this <command moreinfo="none">smbd</command>.  This is a 
            restriction of the SMB/CIFS protocol when in <command moreinfo="none">security = server
            </command> mode and cannot be fixed in Samba.</para>
        </listitem>
            
        <listitem>
            <para>If you are using a Windows NT server as your 
            password server then you will have to ensure that your users 
            are able to login from the Samba server, as when in <command moreinfo="none">
            security = server</command>  mode the network logon will appear to 
            come from there rather than from the users workstation.</para>
        </listitem>
    </itemizedlist>
</description>

<related>security</related>
<value type="default">*</value>
<value type="example">NT-PDC, NT-BDC1, NT-BDC2, *</value>
<value type="example">windc.mydomain.com:389 192.168.1.101 *</value>
</samba:parameter>