updated

LDP/faq/docbook/Linux-FAQ.sgml

@@ -368,8 +368,8 @@ source code distribution.
 A project has been underway for a while to port Linux to suitable
 68000-series based systems like Amigas and Ataris. The Linux/m68K FAQ
 is located at 
-<ulink url="http://www.linux-m68k.org/faq/faq.html">
-<literal>http://www.linux-m68k.org/faq/faq.html</literal>
+<ulink url="http://www.clark.net/pub/lawrencc/linux/faq/faq.html">
+<literal>http://www.clark.net/pub/lawrencc/linux/faq/faq.html</literal>
 </ulink>. The URL of the Linux/m68k home page is 
 <ulink url="http://www.linux-m68k.org">
 <literal>http://www.linux-m68k.org</literal></ulink>.
@@ -3846,7 +3846,8 @@ directory <filename>/etc/pam/</filename> or
 <filename>/etc/pam.d/</filename>.  If the corresponding authentication
 file doesn't exist, the instructions for configuring FTP and Telnet
 authentication and other PAM configuration, should be in
-<literal>/usr/doc/pam-&lt;version&gt;</literal>.
+<literal>/usr/doc/pam-&lt;version&gt;</literal>. Refer also to the 
+answer for ``<xref linkend="ftp-421-error" endterm="ftp-421-error">.''
 </para>
 <para>
 If it's an FTP server on an older system, make sure that the account
@@ -6985,6 +6986,35 @@ page, and/or the settings in <filename>/etc/sysconfig/init</filename>.
 </para>
 </sect2>
 
+<sect2 label="10.25">
+<title id="ftp-421-error">
+FTP server says: ``421 service not available, remote server has closed connection.''
+</title>
+<para>
+If an FTP server won't allow logins, it is probably configured 
+correctly, but the problem is probably with authorizing users at login.
+FTP servers in current distriubtions often authorize users with the 
+Pluggable Authentication Modules library, in which case there should
+be an authorization file <filename>/etc/pam.d/ftp</filename>.  A 
+generic authorization file looks like this. (The line break on the
+first ``auth'' line is for readability. The entry is actually a single,
+long line:)
+</para>
+<para><screen>
+   #%PAM-1.0
+   auth       required	/lib/security/pam_listfile.so item=user \
+	      sense=deny file=/etc/ftpusers onerr=succeed
+   auth       required	/lib/security/pam_pwdb.so shadow nullok
+   auth       required	/lib/security/pam_shells.so
+   account    required	/lib/security/pam_pwdb.so
+   session    required	/lib/security/pam_pwdb.so
+</screen></para>
+<para>
+Also, make sure the <filename>/etc/ftpusers</filename> file, or whatever
+users file is named in the first ``auth'' line, is configured correctly.
+</para>
+</sect2>
+
 </sect1>