Remote Bridging with IP Tunnels mini-HOWTO
Alexander Alekseev
alex@zapad.msk.ru
yomoyomo - 日本語訳
ymgrtq@ma.neweb.ne.jp
v1.0, May 12, 2002
Revision History
Revision 1.0 2002-05-12 Revised by: aa
first release
この文書は、2つの独立したイーサネット LAN の間に IP トンネルを張り、そ
れらを結合する方法を解説するものです。
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Table of Contents
1. どのように動作するか?
1.1. 2つの LAN 間のイーサネットトラフィックを IP でブリッジング
1.2. 他のプロトコルはどうでしょう?
2. Copyright
2.1. GNU Free Documentation License
2.2. PREAMBLE
2.3. APPLICABILITY AND DEFINITIONS
2.4. VERBATIM COPYING
2.5. COPYING IN QUANTITY
2.6. MODIFICATIONS
2.7. COMBINING DOCUMENTS
2.8. COLLECTIONS OF DOCUMENTS
2.9. AGGREGATION WITH INDEPENDENT WORKS
2.10. TRANSLATION
2.11. TERMINATION
2.12. FUTURE REVISIONS OF THIS LICENSE
2.13. How to use this License for your documents
3. 日本語訳について
1. どのように動作するか?
2つのイーサネット LAN がともにインターネットに接続していれば、 LAN 間の
トラフィックを透過的にブリッジしてイーサネット LAN を結合できます。
"本物の"ブリッジングを行えるわけではなく、Linux がルーティングできる第
三層のプロトコルをブリッジすることしかできませんが、これでイーサネット
のトラフィックがブリッジされているように見えます。 2つのイーサネットブ
リッジにより、IP や IPX のトラフィックをブリッジできます。それ以外の第
三層プロトコルに関しては、独立した LAN 間のトラフィックを透過的にブリッ
ジすることはできません。他のプロトコルをブリッジできるかどうか判断する
には、この文書の残りを読んでください。
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1.1. 2つの LAN 間のイーサネットトラフィックを IP でブリッジング
以下の環境を想定します:
┌──────────────────────────────────┐
│PC1 (192.168.0.1 /24)--| │
│PC3 (192.168.0.3 /24)--| │
│PC5 (192.168.0.5 /24)--|--[ eth0 - bridge_1 - eth1 (195.0.0.1) ] │
│ │
│PC253 (192.168.0.253/24)--| │
│ | (192.168.0.2 /24) PC2 │
│ | (192.168.0.4 /24) PC4 │
│[ (192.0.0.1) eth1 - bridge_2 - eth0 ] --| (192.168.0.6 /24) PC6 │
│ │
│ | (192.168.0.254/24) PC254 │
└──────────────────────────────────┘
bridge_1 と bridge_2 が Linux ブリッジで、それらはインターネットインタ
フェースである eth1 で外部接続しています。よって 195.0.0.1 と 192.0.0.1
は、ISP から与えられた有効なインターネットアドレスなら何でもかまいませ
ん。
では、以下のことを行います:
1. カーネル 2.2 もしくは 2.4 の入った Linux マシンを2台用意してくださ
い。カーネルをコンパイルする際に PPP と Advanced Router を有効にし
ます。また、iproute2 パッケージを適切にインストールする必要もありま
す。iproute2 に関する情報は、カーネルの Configure.help における
Advanced Router の項目のコメントにあります。さらに以下のユーティリ
ティも必要です:
□ pppd (PPP デーモン) - ftp://cs.anu.edu.au/pub/software/ppp/
□ PopTop (PPTP サーバ) - http://poptop.lineo.com
□ PPTP (C.S. Ananian 作の Linux PPTP クライアント) - http://
www.pdos.lcs.mit.edu/~cananian/Projects/PPTP/
□ tarpd (単純なプロクシ ARP デーモン) - htp://www.cs.hut.fi/
~tricky/utils/net/tarpd-1.6.tar.gz
以上のソフトウェアは http://www.freshmeat.net でも見つけられます。
MS Chap と MS Encryption (MPPE) を行いたければ、pppd とカーネルに特
別なパッチが必要であることを憶えておいてください。パッチの入手とイ
ンストール方法についての解説は、 PoPTop のマニュアルを参照ください
。
2. ルータをインターネットに接続するか、さもなくば IP 以外のプロトコル
でなければどんなプロトコルでもいいですから、二点間の通信を確立して
ください。
3. 二点間に PPTP トンネルを張ってください。PoPToP (サーバ側)や pptp
(クライアント側)のマニュアルに設定例があります。
4. ここまでで2つのブリッジの間に IP トンネルが張れたはずです。暗号化さ
れていることもあるでしょう (PPP のマニュアルを参照)。ブリッジングの
設定を行いましょう。
5. ここでのブリッジは実際にはルータなので、ブリッジ上で以下のコマンド
を走らせる必要があることをお忘れなく(bridge_1 と bridge_2 を、ブリ
ッジ間の PPTP トンネルのそれぞれの終端に割り当てられた IP アドレス
だと仮定):
┌────────────────────────────┐
│ bridge_1$ip route add 192.168.0.2 via bridge_2 │
│ bridge_1$ip route add 192.168.0.4 via bridge_2 │
│ bridge_1$ip route add 192.168.0.6 via bridge_2 │
│ │
│ bridge_1$ip route add 192.168.0.254 via bridge_2 │
│ bridge_1$ip route add 192.168.0.255 via bridge_2 │
│ │
└────────────────────────────┘
もう片側では以下のコマンドを実行します:
┌────────────────────────────┐
│ bridge_2$ip route add 192.168.0.1 via bridge_1 │
│ bridge_2$ip route add 192.168.0.3 via bridge_1 │
│ bridge_2$ip route add 192.168.0.5 via bridge_1 │
│ │
│ bridge_2$ip route add 192.168.0.253 via bridge_1 │
│ │
└────────────────────────────┘
こうして各ブリッジに、どの端末が相手側にいるのかを指定します。昔な
がらの route コマンドでも同じことができます。以下のような感じです:
┌────────────────────────────┐
│ bridge_1$route add -host 192.168.0.2 gw bridge_2 │
│ bridge_1$route add -host 192.168.0.4 gw bridge_2 │
│ bridge_1$route add -host 192.168.0.6 gw bridge_2 │
│ │
│ bridge_1$route add -host 192.168.0.254 gw bridge_2 │
│ bridge_1$route add -host 192.168.0.255 gw bridge_2 │
│ │
└────────────────────────────┘
もう片側では以下のコマンドを実行します:
┌────────────────────────────┐
│ bridge_2$route add -host 192.168.0.1 gw bridge_1 │
│ bridge_2$route add -host 192.168.0.3 gw bridge_1 │
│ bridge_2$route add -host 192.168.0.5 gw bridge_1 │
│ │
│ bridge_2$route add -host 192.168.0.253 gw bridge_1 │
│ │
└────────────────────────────┘
もう一度注意しておきますが、 bridge_1 と bridge_2 は ISP から付与さ
れた IP アドレスではなく、あなたが PPTP トンネルの各終端に割り当て
た IP アドレスです。
6. これでブリッジが2つでき、いずれのブリッジも特定の IP アドレスがある
場所を把握しています。しかし、リモートネットワーク宛てのトラフィッ
クをローカルのブリッジに送信するようコンピュータに指定するにはどう
すればよいでしょう。その場合 tarpd が必要になります。
tarpd は非常にシンプルなデーモンであり、特定の IP アドレス宛ての
ARP リクエストに応答します。各ブリッジ上で tarpd を走らせ、相手側の
端末に割り当てられた IP アドレスのリストを指定するだけでよいです。
例えば、上に示した二つのブリッジの場合、以下を実行します:
┌────────────────────────────┐
│ bridge_1$tarpd eth0 192.168.0.2 255.255.255.255 \ │
│ 192.168.0.4 255.255.255.255 \ │
│ │
│ 192.168.0.254 255.255.255.255 │
│ │
└────────────────────────────┘
もう片側では以下のコマンドを実行します:
┌────────────────────────────┐
│ bridge_2$tarpd eth0 192.168.0.1 255.255.255.255 \ │
│ 192.168.0.3 255.255.255.255 \ │
│ │
│ 192.168.0.253 255.255.255.255 │
│ │
└────────────────────────────┘
各ブリッジにリモート設定を128組行います(IPアドレスとマスクアドレス
。 tarped を混乱させないように、マスクアドレスは 255.255.255.255 に
すべき!)。
7. 通信がブリッジされるのをお楽しみください!
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1.2. 他のプロトコルはどうでしょう?
実のところ、他のプロトコルのルーティングについては何も言えません。私は
利用したことがないのです。しかし、他のプロトコルに精通していれば、この
文書で示したようにブリッジすることは難しくはないはずだと思います。
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2. Copyright
Copyright 2002 Alexander Alekseev
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".
(日本語訳)この文書の複製、配布、修正は、Free Software Foundation により
公開されている、GNU Free Documentation License バージョン 1.1、もしくは
それ以降のバージョンの元で許可されます。ただし、この文書には GFDL で規
定されている「変更不可部分」はありませんし、また表紙テキストや裏表紙テ
キストなどもありません。このライセンスのコピーは、"GNU Free
Documentation License" というタイトルのセクションに収録されています。
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2.1. GNU Free Documentation License
Version 1.1, March 2000
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.
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2.2. PREAMBLE
The purpose of this License is to make a manual, textbook, or other
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2.3. APPLICABILITY AND DEFINITIONS
This License applies to any manual or other work that contains a notice
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2.4. VERBATIM COPYING
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2.6. MODIFICATIONS
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2.9. AGGREGATION WITH INDEPENDENT WORKS
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2.10. TRANSLATION
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.
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2.11. TERMINATION
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.
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2.12. FUTURE REVISIONS OF THIS LICENSE
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 http://www.gnu.org/
copyleft/.
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.
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2.13. How to use this License for your documents
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:
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".
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.
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.
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3. 日本語訳について
日本語訳は Linux Japanese FAQ Project が行いました。翻訳に関するご意見
は JF プロジェクト 宛に連絡してください。
v1.0j
翻訳:
yomoyomo
校正(50音順):
□ 中野武雄さん
□ 水原文さん
□ 山下義之さん