📄 251-251.html
字号:
<HTML>
<HEAD>
<TITLE>Special Edition Using Linux, Fourth Edition:Improving System Security</TITLE>
<META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW">
<SCRIPT>
<!--
function displayWindow(url, width, height) {
var Win = window.open(url,"displayWindow",'width=' + width +
',height=' + height + ',resizable=1,scrollbars=yes');
}
//-->
</SCRIPT>
</HEAD>
-->
<!--ISBN=0789717468//-->
<!--TITLE=Special Edition Using Linux, Fourth Edition//-->
<!--AUTHOR=Jack Tackett//-->
<!--AUTHOR=Jr.//-->
<!--AUTHOR=Steve Burnett//-->
<!--PUBLISHER=Macmillan Computer Publishing//-->
<!--IMPRINT=Que//-->
<!--CHAPTER=12//-->
<!--PAGES=251-251//-->
<!--UNASSIGNED1//-->
<!--UNASSIGNED2//-->
<CENTER>
<TABLE BORDER>
<TR>
<TD><A HREF="248-251.html">Previous</A></TD>
<TD><A HREF="../ewtoc.html">Table of Contents</A></TD>
<TD><A HREF="../ch13/253-255.html">Next</A></TD>
</TR>
</TABLE>
</CENTER>
<P><BR></P>
<P><FONT SIZE="+1"><B>Enabling Dial-Up Passwords</B></FONT></P>
<P>If you want to limit who can dial in and connect, dial-up passwords allow you to control who accesses the systems remotely. To enable the use of dial-up passwords, you must examine the file /etc/login.defs and see that DIALUPS_CHECK_ENAB is set to Yes.
</P>
<P>Two files contain the dial-up information:</P>
<DL>
<DD><B>•</B> <I>/etc/dialups</I> contains the ttys (one per line, with the leading “/dev/” removed). If a tty is listed, dial-up checks are performed.
<DD><B>•</B> <I>/etc/d_passwd</I> contains the fully qualified path name of a shell, followed by an optional password.
</DL>
<P>If a user logs into a line that is listed in /etc/dialups and his shell is listed in the file /etc/d_passwd, he will be allowed access only by entering the correct dial-up password.
</P>
<P>The command <TT>dpasswd</TT> assigns passwords to the shells in the /etc/d_passwd file.</P>
<H3><A NAME="Heading30"></A><FONT COLOR="#000077">From Here…</FONT></H3>
<P>You can find more information about security issues in the following chapters:
</P>
<DL>
<DD><B>•</B> Chapter 10, “Managing User Accounts,” discusses the issues relating to creating and maintaining user accounts on Linux.
<DD><B>•</B> Chapter 11, “Backing Up Data,” describes how to set up and maintain backups of your system.
</DL>
<P><BR></P>
<CENTER>
<TABLE BORDER>
<TR>
<TD><A HREF="248-251.html">Previous</A></TD>
<TD><A HREF="../ewtoc.html">Table of Contents</A></TD>
<TD><A HREF="../ch13/253-255.html">Next</A></TD>
</TR>
</TABLE>
</CENTER>
</td>
</tr>
</table>
<!-- begin footer information -->
</body></html>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -