forked from extern/shorewall_code
1cd0d84a16
git-svn-id: https://shorewall.svn.sourceforge.net/svnroot/shorewall/trunk@8608 fbd18981-670d-0410-9b5c-8dc0c1a9a2bb
97 lines
3.9 KiB
XML
97 lines
3.9 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
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"http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd">
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<article>
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<!--$Id$-->
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<articleinfo>
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<title>KVM (Kernel-mode Virtual Machine)</title>
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<authorgroup>
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<author>
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<firstname>Tom</firstname>
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<surname>Eastep</surname>
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</author>
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</authorgroup>
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<pubdate><?dbtimestamp format="Y/m/d"?></pubdate>
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<copyright>
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<year>2008</year>
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<holder>Thomas M. Eastep</holder>
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</copyright>
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<legalnotice>
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<para>Permission is granted to copy, distribute and/or modify this
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document under the terms of the GNU Free Documentation License, Version
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1.2 or any later version published by the Free Software Foundation; with
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no Invariant Sections, with no Front-Cover, and with no Back-Cover
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Texts. A copy of the license is included in the section entitled
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<quote><ulink url="GnuCopyright.htm">GNU Free Documentation
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License</ulink></quote>.</para>
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</legalnotice>
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</articleinfo>
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<section>
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<title>Introduction</title>
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<para>Kernel-mode Virtual Machines (<ulink
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url="http://kvm.qumranet.com/">http://kvm.qumranet.com/</ulink>) is a
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virtualization platform that leverages the virtualization capabilities
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available with current microprocessors from both
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<trademark>Intel</trademark> and <trademark>AMD</trademark>. For an
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overview of KVM, please see my <ulink
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url="http://www.shorewall.net/Linuxfest-2008.pdf">2008 Linuxfest Northwest
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presentation</ulink>.</para>
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<para>I use KVM to implement a number of virtual machines running various
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Linux Distributions. The following diagram shows the entire
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network.</para>
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<graphic align="center" fileref="images/Network2008.png" />
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<para>My personal laptop (Ursa) hosts the virtual machines. As shown in
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the diagram, Ursa has routes to the internet through both the
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<trademark>Linksys</trademark> WRT300N and through my Shorewall firewall.
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This allows me to test the <ulink url="MultiISP.html">Shorewall Multi-ISP
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feature</ulink>, even though I only have a single internet
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connection</para>
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<para>The Linux Bridges shown in the diagram are, of course, actually
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within their associated system (Firewall or Ursa) but I've pictured them
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separately.</para>
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</section>
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<section>
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<title>Networking Configuration</title>
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<para>I use a network configuration where each VM has it's own VNET and
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tap device and the tap devices are all configured as ports on a Linux
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Bridge. For clarity, I've only shown four of the virtual machines
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available on the system.</para>
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<graphic align="center" fileref="images/KVM1.png" />
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<para>I run a DHCP server on the host to assign IP addresses to the VMs
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and I also run dmsmasq to act as a nameserver for the VMs. The latter is
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important when I take the laptop on the road. I'm currently running a
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separate ISC DHCP server but I have it on my todo list to configure
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dnsmasq as a DHCP server, thus eliminating one process on the
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system.</para>
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<para>The bridge is configured using the script described in my Linuxfest
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presentation linked above. The script may be found at <ulink
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url="http://www.shorewall.net/pub/shorewall/contrib/kvm/kvm">http://www.shorewall.net/pub/shorewall/contrib/kvm/kvm</ulink>.</para>
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<para>With this configuration, and with only a single network interface on
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the laptop, this is just a simple <ulink
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url="two-interface.xml">two-interface masquerading setup</ulink> where the
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local network interface is <filename class="devicefile">br0</filename>. As
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with all bridges, <filename class="devicefile">br0</filename> must be
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configured with the <option>routeback</option> option in <ulink
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url="manpages/shorewall-interfaces.html">shorewall-interfaces</ulink>(5).</para>
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</section>
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</article>
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