mirror of https://github.com/tLDP/LDP
new; moved from linuxdoc
This commit is contained in:
parent
18b4978592
commit
e789566b1f
|
@ -0,0 +1,739 @@
|
|||
<!DOCTYPE ARTICLE PUBLIC "-//OASIS//DTD DocBook V4.1//EN"[]>
|
||||
|
||||
<article>
|
||||
<title>Bridging mini-HOWTO</title>
|
||||
<!-- Title information -->
|
||||
<articleinfo>
|
||||
<author>
|
||||
<firstname>Christopher </firstname>
|
||||
<surname>Cole</surname>
|
||||
<affiliation>
|
||||
<address>
|
||||
<email>cole@coledd.com</email>
|
||||
</address>
|
||||
</affiliation>
|
||||
</author>
|
||||
<pubdate>v1.21, March 7, 2001</pubdate>
|
||||
<revhistory>
|
||||
<revision>
|
||||
<revnumber></revnumber>
|
||||
<date>May 20, 2002</date>
|
||||
<authorinitials>tab</authorinitials>
|
||||
<revremark>Converted to Docbook 4.1 SGML and added GFDL per Christopher Cole</revremark>
|
||||
</revision>
|
||||
</revhistory>
|
||||
<abstract>
|
||||
<para>This document describes how to setup an ethernet bridge. What
|
||||
is an ethernet bridge? An ethernet bridge is a device that controls data
|
||||
packets within a subnet in an attempt to cut down the amount of traffic.
|
||||
A bridge is usually placed between two separate groups of computers that
|
||||
talk within themselves, but not so much with the computers in the other
|
||||
group. A good example of this is to consider a cluster of Macintoshes and
|
||||
a cluster of unix machines. Both of these groups of machines tend to be
|
||||
quite chatty amongst themselves, and the traffic they produce on the
|
||||
network causes collisions for the other machines who are trying to speak
|
||||
to one another. A bridge would be placed between these groups of
|
||||
computers. The job of the bridge is then to examine the destination of
|
||||
the data packets one at a time and decide whether or not to pass the
|
||||
packets to the other side of the ethernet segment. The result is a
|
||||
faster, quieter network with less collisions.
|
||||
</para>
|
||||
</abstract>
|
||||
</articleinfo>
|
||||
<!-- Table of contents -->
|
||||
|
||||
|
||||
<sect1>
|
||||
<title>Setup</title>
|
||||
<para>
|
||||
<itemizedlist>
|
||||
<listitem>
|
||||
<para>Get Bridge Config:
|
||||
<ulink url="ftp://ftp.tux.org/people/alan-cox/BRCFG.tgz"> BRCFG.tgz</ulink>
|
||||
</para>
|
||||
</listitem>
|
||||
|
||||
<listitem>
|
||||
<para>BRCFG may also be found at:
|
||||
<ulink url="http://coledd.com/networking/bridge/"> http://coledd.com/networking/bridge</ulink>
|
||||
</para>
|
||||
</listitem>
|
||||
|
||||
<listitem>
|
||||
<para>Enable multiple ethernet devices on your machine by
|
||||
adding this line to your <filename>/etc/lilo.conf</filename>,
|
||||
and re-run <application>lilo</application>:
|
||||
<screen>append = "ether=0,0,eth1"</screen>
|
||||
</para>
|
||||
<para>If you have three interfaces on your bridge, use this line instead:
|
||||
<screen>append = "ether=0,0,eth1 ether=0,0,eth2"</screen>
|
||||
</para>
|
||||
<para>More interfaces can be found by adding more ether statements.
|
||||
By default a stock Linux kernel probes for a single ethercard,
|
||||
and once one is found the probe ceases. The above append statement
|
||||
tells the kernel to keep probing for more ethernet devices after the
|
||||
first one is found.
|
||||
Alternatively, the boot parameter can be used instead:
|
||||
<screen>linux ether=0,0,eth1</screen>
|
||||
</para>
|
||||
<para>Or, with 3 interfaces, use:
|
||||
<screen>linux ether=0,0,eth1 ether=0,0,eth2</screen>
|
||||
</para>
|
||||
</listitem>
|
||||
|
||||
<listitem>
|
||||
<para>Recompile the kernel with <envar>BRIDGING</envar> enabled.
|
||||
</para>
|
||||
</listitem>
|
||||
|
||||
<listitem>
|
||||
<para>A bridge should not have an IP address.
|
||||
It CAN, but a plain bridge doesn't need one.
|
||||
To remove the IP address from your bridge, go to
|
||||
<filename>/etc/sysconfig/network-scripts/</filename> (for a RedHat system)
|
||||
and copy <filename>ifcfg-lo0</filename> to <filename>ifcfg-eth0</filename> &
|
||||
<filename>ifcfg-eth1</filename>.
|
||||
In these two new files, change the line containing
|
||||
<userinput>DEVICE=lo</userinput> to <userinput>DEVICE=eth0</userinput>
|
||||
and <userinput>DEVICE=eth1</userinput>.
|
||||
Since other distributions may deviate from this, you may need to refer to additional
|
||||
documentation.
|
||||
If there are more than 2 interfaces to this bridge,
|
||||
be sure to make the corresponding configurations to those, as well.
|
||||
</para>
|
||||
</listitem>
|
||||
|
||||
<listitem>
|
||||
<para>Reboot so you are running the new kernel with <envar>BRIDGING</envar> in it,
|
||||
and also to make sure that an IP addresses are not bound to the
|
||||
network interfaces.
|
||||
</para>
|
||||
</listitem>
|
||||
|
||||
<listitem>
|
||||
<para>Once the system is backed up, put the ethernet cards into promiscuous mode,
|
||||
so they will look at every packet that passes by its interface:
|
||||
<screen>ifconfig eth0 promisc ; ifconfig eth1 promisc</screen>
|
||||
All interfaces which are connected to network segments to be bridged
|
||||
are to be put into promiscuous mode.
|
||||
</para>
|
||||
</listitem>
|
||||
|
||||
<listitem>
|
||||
<para>Turn bridging ON using the <application>brcfg</application> program:
|
||||
<screen>brcfg -ena</screen>
|
||||
</para>
|
||||
</listitem>
|
||||
|
||||
<listitem>
|
||||
<para>Verify that there is different traffic on each interface:
|
||||
<screen>
|
||||
tcpdump -i eth0 (in one window)
|
||||
tcpdump -i eth1 (in another window)
|
||||
</screen>
|
||||
</para>
|
||||
</listitem>
|
||||
|
||||
<listitem>
|
||||
<para>Run a sniffer or <application>tcpdump</application> on another machine
|
||||
to verify the bridge is separating the segment correctly.
|
||||
</para>
|
||||
</listitem>
|
||||
</itemizedlist>
|
||||
</para>
|
||||
</sect1>
|
||||
|
||||
|
||||
<sect1>
|
||||
<title>Common Problems</title>
|
||||
|
||||
<qandaset defaultlabel='qanda'>
|
||||
<qandaentry>
|
||||
<question>
|
||||
<para>I get the message <errorname>ioctl(SIOCGIFBR) failed: Package not installed
|
||||
</errorname>. What does this mean?</para>
|
||||
</question>
|
||||
<answer>
|
||||
<para>You don't have bridging capability in your kernel.
|
||||
Get a 2.0 or greater kernel,
|
||||
and recompile with the <envar>BRIDGING</envar> option enabled.</para>
|
||||
</answer>
|
||||
</qandaentry>
|
||||
|
||||
<qandaentry>
|
||||
<question>
|
||||
<para>Machines on one side cannot ping the other side!</para>
|
||||
</question>
|
||||
<answer>
|
||||
<itemizedlist spacing=compact>
|
||||
<listitem><simpara>Did you enable bridging using <application>brcfg -ena</application>? (<application>brcfg</application> should say <returnvalue>bridging is ENABLED</returnvalue>)</simpara>
|
||||
</listitem>
|
||||
<listitem><simpara>Did you put the interfaces into promiscuous mode?
|
||||
(issue the <application>ifconfig</application> command.
|
||||
The <property>PROMISC</property> flag should be on for
|
||||
both interfaces.)</simpara>
|
||||
</listitem>
|
||||
<listitem><simpara>If using multiple-media interface adapters,
|
||||
make sure that the correct one is enabled.
|
||||
You may need to use the config/setup program that
|
||||
came with the network interface card.</simpara>
|
||||
</listitem>
|
||||
</itemizedlist>
|
||||
</answer>
|
||||
</qandaentry>
|
||||
|
||||
<qandaentry>
|
||||
<question>
|
||||
<para>I cannot <application>telnet</application>/<application>ftp</application> from the bridge! Why?</para>
|
||||
</question>
|
||||
<answer>
|
||||
<para>This is because there is no IP address bound to any of bridge
|
||||
interfaces. A bridge is to be a transparent part of a network.</para>
|
||||
</answer>
|
||||
</qandaentry>
|
||||
|
||||
<qandaentry>
|
||||
<question>
|
||||
<para>What do I need to set up in the way of routing?</para>
|
||||
</question>
|
||||
<answer>
|
||||
<para>Nothing!
|
||||
All routing intelligence is handled by
|
||||
the bridging code in the kernel.
|
||||
To see the ethernet addresses as they are learned by the bridge,
|
||||
use the <application>brcfg</application> program in debug mode:</para>
|
||||
<screen>
|
||||
brcfg -deb
|
||||
</screen>
|
||||
</answer>
|
||||
</qandaentry>
|
||||
|
||||
<qandaentry>
|
||||
<question>
|
||||
<para>The bridge appears to work, but why doesn't <application>traceroute</application> show the bridge as a part of the path?</para>
|
||||
</question>
|
||||
<answer>
|
||||
<para>Due to the nature of a bridge, a <application>traceroute</application> should NOT show the bridge as a part of the path. A bridge is to be a transparent component of the network.</para>
|
||||
</answer>
|
||||
</qandaentry>
|
||||
|
||||
<qandaentry>
|
||||
<question>
|
||||
<para>Is it necessary to compile <envar>IP_FORWARD</envar> into the kernel?</para>
|
||||
</question>
|
||||
<answer>
|
||||
<para>No. The bridging code in the kernel takes care of the packet
|
||||
transport.
|
||||
<envar>IP_FORWARD</envar> is for a gateway that has IP addresses
|
||||
bound to its interfaces.</para>
|
||||
</answer>
|
||||
</qandaentry>
|
||||
|
||||
<qandaentry>
|
||||
<question>
|
||||
<para>Why are the physical ethernet addresses for port 1 and port 2 the
|
||||
same according to the <application>brcfg</application> program?
|
||||
Shouldn't they be different?</para>
|
||||
</question>
|
||||
<answer>
|
||||
<para>No. Every port on a bridge intentionally is assigned the same
|
||||
physical ethernet address by the bridging code.</para>
|
||||
</answer>
|
||||
</qandaentry>
|
||||
|
||||
<qandaentry>
|
||||
<question>
|
||||
<para>Bridging does not appear to be an option when performing a make
|
||||
config on the kernel. How does one enable it?</para>
|
||||
</question>
|
||||
<answer>
|
||||
<para>During the kernel config, answer <quote>Y</quote> to the question, <prompt>Prompt for
|
||||
development and/or incomplete code/drivers (CONFIG_EXPERIMENTAL) [Y/n/?]</prompt>.</para>
|
||||
</answer>
|
||||
</qandaentry>
|
||||
|
||||
<qandaentry>
|
||||
<question>
|
||||
<para>Too many hubs (4 or more) are chained one after another in series,
|
||||
cause timing problems on an ethernet. What effect does a bridge
|
||||
have in a subnet that is layered with hubs?</para>
|
||||
</question>
|
||||
<answer>
|
||||
<para>A bridge resets the 3/4/5 hubs rule. A bridge does not deal with
|
||||
packets the way a hub does, and is therefore not a contributor to
|
||||
timing problems on a network.</para>
|
||||
</answer>
|
||||
</qandaentry>
|
||||
|
||||
<qandaentry>
|
||||
<question>
|
||||
<para>Can a bridge interface to both 10Mb and 100Mb ethernet segments?
|
||||
Will such a configuration slow down the rest of the traffic on the
|
||||
high speed side?</para>
|
||||
</question>
|
||||
<answer>
|
||||
<para>Yes, a bridge can tie together a 10Mb segment with a 100Mb segment.
|
||||
As long as the network card on the fast network is 100Mb capable,
|
||||
TCP takes care of the rest. While it's true that the
|
||||
packets from a host in the 100Mb network communicating to a host
|
||||
in the 10Mb network are moving at only 10Mb/s, the rest of the
|
||||
traffic on the fast ethernet is not slowed down.</para>
|
||||
</answer>
|
||||
</qandaentry>
|
||||
</qandaset>
|
||||
|
||||
</sect1>
|
||||
|
||||
<sect1>
|
||||
<title>Copyright</title>
|
||||
<para>Copyright © 2002 Christopher Cole</para>
|
||||
<para>Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".</para>
|
||||
|
||||
|
||||
<sect2 id="gfdl">
|
||||
<title>GNU Free Documentation License</title>
|
||||
<!-- - GNU Project - Free Software Foundation (FSF) -->
|
||||
<!-- LINK REV="made" HREF="mailto:webmasters@gnu.org" -->
|
||||
|
||||
|
||||
<!-- sect2>
|
||||
<title>GNU Free Documentation License</title -->
|
||||
|
||||
<para>Version 1.1, March 2000</para>
|
||||
|
||||
<blockquote>
|
||||
<para>Copyright (C) 2000 Free Software Foundation, Inc.
|
||||
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
||||
Everyone is permitted to copy and distribute verbatim copies
|
||||
of this license document, but changing it is not allowed.</para>
|
||||
</blockquote>
|
||||
|
||||
<sect2 id="gfdl-0">
|
||||
<title>PREAMBLE</title>
|
||||
|
||||
<para>The purpose of this License is to make a manual, textbook,
|
||||
or other written document "free" in the sense of freedom: to
|
||||
assure everyone the effective freedom to copy and redistribute it,
|
||||
with or without modifying it, either commercially or
|
||||
noncommercially. Secondarily, this License preserves for the
|
||||
author and publisher a way to get credit for their work, while not
|
||||
being considered responsible for modifications made by
|
||||
others.</para>
|
||||
|
||||
<para>This License is a kind of "copyleft", which means that
|
||||
derivative works of the document must themselves be free in the
|
||||
same sense. It complements the GNU General Public License, which
|
||||
is a copyleft license designed for free software.</para>
|
||||
|
||||
<para>We have designed this License in order to use it for manuals
|
||||
for free software, because free software needs free documentation:
|
||||
a free program should come with manuals providing the same
|
||||
freedoms that the software does. But this License is not limited
|
||||
to software manuals; it can be used for any textual work,
|
||||
regardless of subject matter or whether it is published as a
|
||||
printed book. We recommend this License principally for works
|
||||
whose purpose is instruction or reference.</para>
|
||||
</sect2>
|
||||
|
||||
<sect2 id="gfdl-1">
|
||||
<title>APPLICABILITY AND DEFINITIONS</title>
|
||||
|
||||
<para>This License applies to any manual or other work that
|
||||
contains a notice placed by the copyright holder saying it can be
|
||||
distributed under the terms of this License. The "Document",
|
||||
below, refers to any such manual or work. Any member of the
|
||||
public is a licensee, and is addressed as "you".</para>
|
||||
|
||||
<para>A "Modified Version" of the Document means any work
|
||||
containing the Document or a portion of it, either copied
|
||||
verbatim, or with modifications and/or translated into another
|
||||
language.</para>
|
||||
|
||||
<para>A "Secondary Section" is a named appendix or a front-matter
|
||||
section of the Document that deals exclusively with the
|
||||
relationship of the publishers or authors of the Document to the
|
||||
Document's overall subject (or to related matters) and contains
|
||||
nothing that could fall directly within that overall subject.
|
||||
(For example, if the Document is in part a textbook of
|
||||
mathematics, a Secondary Section may not explain any mathematics.)
|
||||
The relationship could be a matter of historical connection with
|
||||
the subject or with related matters, or of legal, commercial,
|
||||
philosophical, ethical or political position regarding
|
||||
them.</para>
|
||||
|
||||
<para>The "Invariant Sections" are certain Secondary Sections
|
||||
whose titles are designated, as being those of Invariant Sections,
|
||||
in the notice that says that the Document is released under this
|
||||
License.</para>
|
||||
|
||||
<para>The "Cover Texts" are certain short passages of text that
|
||||
are listed, as Front-Cover Texts or Back-Cover Texts, in the
|
||||
notice that says that the Document is released under this
|
||||
License.</para>
|
||||
|
||||
<para>A "Transparent" copy of the Document means a
|
||||
machine-readable copy, represented in a format whose specification
|
||||
is available to the general public, whose contents can be viewed
|
||||
and edited directly and straightforwardly with generic text
|
||||
editors or (for images composed of pixels) generic paint programs
|
||||
or (for drawings) some widely available drawing editor, and that
|
||||
is suitable for input to text formatters or for automatic
|
||||
translation to a variety of formats suitable for input to text
|
||||
formatters. A copy made in an otherwise Transparent file format
|
||||
whose markup has been designed to thwart or discourage subsequent
|
||||
modification by readers is not Transparent. A copy that is not
|
||||
"Transparent" is called "Opaque".</para>
|
||||
|
||||
<para>Examples of suitable formats for Transparent copies include
|
||||
plain ASCII without markup, Texinfo input format, LaTeX input
|
||||
format, SGML or XML using a publicly available DTD, and
|
||||
standard-conforming simple HTML designed for human modification.
|
||||
Opaque formats include PostScript, PDF, proprietary formats that
|
||||
can be read and edited only by proprietary word processors, SGML
|
||||
or XML for which the DTD and/or processing tools are not generally
|
||||
available, and the machine-generated HTML produced by some word
|
||||
processors for output purposes only.</para>
|
||||
|
||||
<para>The "Title Page" means, for a printed book, the title page
|
||||
itself, plus such following pages as are needed to hold, legibly,
|
||||
the material this License requires to appear in the title page.
|
||||
For works in formats which do not have any title page as such,
|
||||
"Title Page" means the text near the most prominent appearance of
|
||||
the work's title, preceding the beginning of the body of the
|
||||
text.</para>
|
||||
</sect2>
|
||||
|
||||
<sect2 id="gfdl-2">
|
||||
<title>VERBATIM COPYING</title>
|
||||
|
||||
<para>You may copy and distribute the Document in any medium,
|
||||
either commercially or noncommercially, provided that this
|
||||
License, the copyright notices, and the license notice saying this
|
||||
License applies to the Document are reproduced in all copies, and
|
||||
that you add no other conditions whatsoever to those of this
|
||||
License. You may not use technical measures to obstruct or
|
||||
control the reading or further copying of the copies you make or
|
||||
distribute. However, you may accept compensation in exchange for
|
||||
copies. If you distribute a large enough number of copies you
|
||||
must also follow the conditions in section 3.</para>
|
||||
|
||||
<para>You may also lend copies, under the same conditions stated
|
||||
above, and you may publicly display copies.</para>
|
||||
</sect2>
|
||||
|
||||
<sect2 id="gfdl-3">
|
||||
<title>COPYING IN QUANTITY</title>
|
||||
|
||||
<para>If you publish printed copies of the Document numbering more
|
||||
than 100, and the Document's license notice requires Cover Texts,
|
||||
you must enclose the copies in covers that carry, clearly and
|
||||
legibly, all these Cover Texts: Front-Cover Texts on the front
|
||||
cover, and Back-Cover Texts on the back cover. Both covers must
|
||||
also clearly and legibly identify you as the publisher of these
|
||||
copies. The front cover must present the full title with all
|
||||
words of the title equally prominent and visible. You may add
|
||||
other material on the covers in addition. Copying with changes
|
||||
limited to the covers, as long as they preserve the title of the
|
||||
Document and satisfy these conditions, can be treated as verbatim
|
||||
copying in other respects.</para>
|
||||
|
||||
<para>If the required texts for either cover are too voluminous to
|
||||
fit legibly, you should put the first ones listed (as many as fit
|
||||
reasonably) on the actual cover, and continue the rest onto
|
||||
adjacent pages.</para>
|
||||
|
||||
<para>If you publish or distribute Opaque copies of the Document
|
||||
numbering more than 100, you must either include a
|
||||
machine-readable Transparent copy along with each Opaque copy, or
|
||||
state in or with each Opaque copy a publicly-accessible
|
||||
computer-network location containing a complete Transparent copy
|
||||
of the Document, free of added material, which the general
|
||||
network-using public has access to download anonymously at no
|
||||
charge using public-standard network protocols. If you use the
|
||||
latter option, you must take reasonably prudent steps, when you
|
||||
begin distribution of Opaque copies in quantity, to ensure that
|
||||
this Transparent copy will remain thus accessible at the stated
|
||||
location until at least one year after the last time you
|
||||
distribute an Opaque copy (directly or through your agents or
|
||||
retailers) of that edition to the public.</para>
|
||||
|
||||
<para>It is requested, but not required, that you contact the
|
||||
authors of the Document well before redistributing any large
|
||||
number of copies, to give them a chance to provide you with an
|
||||
updated version of the Document.</para>
|
||||
</sect2>
|
||||
|
||||
<sect2 id="gfdl-4">
|
||||
<title>MODIFICATIONS</title>
|
||||
|
||||
<para>You may copy and distribute a Modified Version of the
|
||||
Document under the conditions of sections 2 and 3 above, provided
|
||||
that you release the Modified Version under precisely this
|
||||
License, with the Modified Version filling the role of the
|
||||
Document, thus licensing distribution and modification of the
|
||||
Modified Version to whoever possesses a copy of it. In addition,
|
||||
you must do these things in the Modified Version:</para>
|
||||
|
||||
<orderedlist numeration="upperalpha">
|
||||
<listitem><para>Use in the Title Page
|
||||
(and on the covers, if any) a title distinct from that of the
|
||||
Document, and from those of previous versions (which should, if
|
||||
there were any, be listed in the History section of the
|
||||
Document). You may use the same title as a previous version if
|
||||
the original publisher of that version gives permission.</para>
|
||||
</listitem>
|
||||
|
||||
<listitem><para>List on the Title Page,
|
||||
as authors, one or more persons or entities responsible for
|
||||
authorship of the modifications in the Modified Version,
|
||||
together with at least five of the principal authors of the
|
||||
Document (all of its principal authors, if it has less than
|
||||
five).</para>
|
||||
</listitem>
|
||||
|
||||
<listitem><para>State on the Title page
|
||||
the name of the publisher of the Modified Version, as the
|
||||
publisher.</para>
|
||||
</listitem>
|
||||
|
||||
<listitem><para>Preserve all the
|
||||
copyright notices of the Document.</para>
|
||||
</listitem>
|
||||
|
||||
<listitem><para>Add an appropriate
|
||||
copyright notice for your modifications adjacent to the other
|
||||
copyright notices.</para>
|
||||
</listitem>
|
||||
|
||||
<listitem><para>Include, immediately
|
||||
after the copyright notices, a license notice giving the public
|
||||
permission to use the Modified Version under the terms of this
|
||||
License, in the form shown in the Addendum below.</para>
|
||||
</listitem>
|
||||
|
||||
<listitem><para>Preserve in that license
|
||||
notice the full lists of Invariant Sections and required Cover
|
||||
Texts given in the Document's license notice.</para>
|
||||
</listitem>
|
||||
|
||||
<listitem><para>Include an unaltered
|
||||
copy of this License.</para>
|
||||
</listitem>
|
||||
|
||||
<listitem><para>Preserve the section
|
||||
entitled "History", and its title, and add to it an item stating
|
||||
at least the title, year, new authors, and publisher of the
|
||||
Modified Version as given on the Title Page. If there is no
|
||||
section entitled "History" in the Document, create one stating
|
||||
the title, year, authors, and publisher of the Document as given
|
||||
on its Title Page, then add an item describing the Modified
|
||||
Version as stated in the previous sentence.</para>
|
||||
</listitem>
|
||||
|
||||
<listitem><para>Preserve the network
|
||||
location, if any, given in the Document for public access to a
|
||||
Transparent copy of the Document, and likewise the network
|
||||
locations given in the Document for previous versions it was
|
||||
based on. These may be placed in the "History" section. You
|
||||
may omit a network location for a work that was published at
|
||||
least four years before the Document itself, or if the original
|
||||
publisher of the version it refers to gives permission.</para>
|
||||
</listitem>
|
||||
|
||||
<listitem><para>In any section entitled
|
||||
"Acknowledgements" or "Dedications", preserve the section's
|
||||
title, and preserve in the section all the substance and tone of
|
||||
each of the contributor acknowledgements and/or dedications
|
||||
given therein.</para>
|
||||
</listitem>
|
||||
|
||||
<listitem><para>Preserve all the
|
||||
Invariant Sections of the Document, unaltered in their text and
|
||||
in their titles. Section numbers or the equivalent are not
|
||||
considered part of the section titles.</para>
|
||||
</listitem>
|
||||
|
||||
<listitem><para>Delete any section
|
||||
entitled "Endorsements". Such a section may not be included in
|
||||
the Modified Version.</para>
|
||||
</listitem>
|
||||
|
||||
<listitem><para>Do not retitle any
|
||||
existing section as "Endorsements" or to conflict in title with
|
||||
any Invariant Section.</para>
|
||||
</listitem>
|
||||
</orderedlist>
|
||||
<para>If the Modified Version includes new front-matter sections
|
||||
or appendices that qualify as Secondary Sections and contain no
|
||||
material copied from the Document, you may at your option
|
||||
designate some or all of these sections as invariant. To do this,
|
||||
add their titles to the list of Invariant Sections in the Modified
|
||||
Version's license notice. These titles must be distinct from any
|
||||
other section titles.</para>
|
||||
|
||||
<para>You may add a section entitled "Endorsements", provided it
|
||||
contains nothing but endorsements of your Modified Version by
|
||||
various parties--for example, statements of peer review or that
|
||||
the text has been approved by an organization as the authoritative
|
||||
definition of a standard.</para>
|
||||
|
||||
<para>You may add a passage of up to five words as a Front-Cover
|
||||
Text, and a passage of up to 25 words as a Back-Cover Text, to the
|
||||
end of the list of Cover Texts in the Modified Version. Only one
|
||||
passage of Front-Cover Text and one of Back-Cover Text may be
|
||||
added by (or through arrangements made by) any one entity. If the
|
||||
Document already includes a cover text for the same cover,
|
||||
previously added by you or by arrangement made by the same entity
|
||||
you are acting on behalf of, you may not add another; but you may
|
||||
replace the old one, on explicit permission from the previous
|
||||
publisher that added the old one.</para>
|
||||
|
||||
<para>The author(s) and publisher(s) of the Document do not by
|
||||
this License give permission to use their names for publicity for
|
||||
or to assert or imply endorsement of any Modified Version.</para>
|
||||
</sect2>
|
||||
|
||||
<sect2 id="gfdl-5">
|
||||
<title>COMBINING DOCUMENTS</title>
|
||||
|
||||
<para>You may combine the Document with other documents released
|
||||
under this License, under the terms defined in section 4 above for
|
||||
modified versions, provided that you include in the combination
|
||||
all of the Invariant Sections of all of the original documents,
|
||||
unmodified, and list them all as Invariant Sections of your
|
||||
combined work in its license notice.</para>
|
||||
|
||||
<para>The combined work need only contain one copy of this
|
||||
License, and multiple identical Invariant Sections may be replaced
|
||||
with a single copy. If there are multiple Invariant Sections with
|
||||
the same name but different contents, make the title of each such
|
||||
section unique by adding at the end of it, in parentheses, the
|
||||
name of the original author or publisher of that section if known,
|
||||
or else a unique number. Make the same adjustment to the section
|
||||
titles in the list of Invariant Sections in the license notice of
|
||||
the combined work.</para>
|
||||
|
||||
<para>In the combination, you must combine any sections entitled
|
||||
"History" in the various original documents, forming one section
|
||||
entitled "History"; likewise combine any sections entitled
|
||||
"Acknowledgements", and any sections entitled "Dedications". You
|
||||
must delete all sections entitled "Endorsements."</para>
|
||||
</sect2>
|
||||
|
||||
<sect2 id="gfdl-6">
|
||||
<title>COLLECTIONS OF DOCUMENTS</title>
|
||||
|
||||
<para>You may make a collection consisting of the Document and
|
||||
other documents released under this License, and replace the
|
||||
individual copies of this License in the various documents with a
|
||||
single copy that is included in the collection, provided that you
|
||||
follow the rules of this License for verbatim copying of each of
|
||||
the documents in all other respects.</para>
|
||||
|
||||
<para>You may extract a single document from such a collection,
|
||||
and distribute it individually under this License, provided you
|
||||
insert a copy of this License into the extracted document, and
|
||||
follow this License in all other respects regarding verbatim
|
||||
copying of that document.</para>
|
||||
</sect2>
|
||||
|
||||
<sect2 id="gfdl-7">
|
||||
<title>AGGREGATION WITH INDEPENDENT WORKS</title>
|
||||
<para>A compilation of the Document or its derivatives with other
|
||||
separate and independent documents or works, in or on a volume of
|
||||
a storage or distribution medium, does not as a whole count as a
|
||||
Modified Version of the Document, provided no compilation
|
||||
copyright is claimed for the compilation. Such a compilation is
|
||||
called an "aggregate", and this License does not apply to the
|
||||
other self-contained works thus compiled with the Document, on
|
||||
account of their being thus compiled, if they are not themselves
|
||||
derivative works of the Document.</para>
|
||||
|
||||
<para>If the Cover Text requirement of section 3 is applicable to
|
||||
these copies of the Document, then if the Document is less than
|
||||
one quarter of the entire aggregate, the Document's Cover Texts
|
||||
may be placed on covers that surround only the Document within the
|
||||
aggregate. Otherwise they must appear on covers around the whole
|
||||
aggregate.</para>
|
||||
</sect2>
|
||||
|
||||
<sect2 id="gfdl-8">
|
||||
<title>TRANSLATION</title>
|
||||
|
||||
<para>Translation is considered a kind of modification, so you may
|
||||
distribute translations of the Document under the terms of section
|
||||
4. Replacing Invariant Sections with translations requires
|
||||
special permission from their copyright holders, but you may
|
||||
include translations of some or all Invariant Sections in addition
|
||||
to the original versions of these Invariant Sections. You may
|
||||
include a translation of this License provided that you also
|
||||
include the original English version of this License. In case of
|
||||
a disagreement between the translation and the original English
|
||||
version of this License, the original English version will
|
||||
prevail.</para>
|
||||
</sect2>
|
||||
|
||||
<sect2 id="gfdl-9">
|
||||
<title>TERMINATION</title>
|
||||
<para>You may not copy, modify, sublicense, or distribute the
|
||||
Document except as expressly provided for under this License. Any
|
||||
other attempt to copy, modify, sublicense or distribute the
|
||||
Document is void, and will automatically terminate your rights
|
||||
under this License. However, parties who have received copies, or
|
||||
rights, from you under this License will not have their licenses
|
||||
terminated so long as such parties remain in full
|
||||
compliance.</para>
|
||||
</sect2>
|
||||
|
||||
<sect2 id="gfdl-10">
|
||||
<title>FUTURE REVISIONS OF THIS LICENSE</title>
|
||||
|
||||
<para>The Free Software Foundation may publish new, revised
|
||||
versions of the GNU Free Documentation License from time to time.
|
||||
Such new versions will be similar in spirit to the present
|
||||
version, but may differ in detail to address new problems or
|
||||
concerns. See <ulink
|
||||
url="http://www.gnu.org/copyleft/">http://www.gnu.org/copyleft/</ulink>.</para>
|
||||
|
||||
<para>Each version of the License is given a distinguishing
|
||||
version number. If the Document specifies that a particular
|
||||
numbered version of this License "or any later version" applies to
|
||||
it, you have the option of following the terms and conditions
|
||||
either of that specified version or of any later version that has
|
||||
been published (not as a draft) by the Free Software Foundation.
|
||||
If the Document does not specify a version number of this License,
|
||||
you may choose any version ever published (not as a draft) by the
|
||||
Free Software Foundation.</para>
|
||||
</sect2>
|
||||
|
||||
<sect2 id="gfdl-11">
|
||||
<title>How to use this License for your documents</title>
|
||||
|
||||
<para>To use this License in a document you have written, include
|
||||
a copy of the License in the document and put the following
|
||||
copyright and license notices just after the title page:</para>
|
||||
|
||||
<blockquote><para>
|
||||
Copyright (c) YEAR YOUR NAME.
|
||||
Permission is granted to copy, distribute and/or modify this document
|
||||
under the terms of the GNU Free Documentation License, Version 1.1
|
||||
or any later version published by the Free Software Foundation;
|
||||
with the Invariant Sections being LIST THEIR TITLES, with the
|
||||
Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.
|
||||
A copy of the license is included in the section entitled "GNU
|
||||
Free Documentation License".
|
||||
</para></blockquote>
|
||||
|
||||
<para>If you have no Invariant Sections, write "with no Invariant
|
||||
Sections" instead of saying which ones are invariant. If you have
|
||||
no Front-Cover Texts, write "no Front-Cover Texts" instead of
|
||||
"Front-Cover Texts being LIST"; likewise for Back-Cover
|
||||
Texts.</para>
|
||||
|
||||
<para>If your document contains nontrivial examples of program
|
||||
code, we recommend releasing these examples in parallel under your
|
||||
choice of free software license, such as the GNU General Public
|
||||
License, to permit their use in free software.</para>
|
||||
</sect2>
|
||||
</sect1>
|
||||
</article>
|
Loading…
Reference in New Issue