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swift 05/08/07 20:09:53 |
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Added: xml/htdocs/doc/en/draft vpnc-howto.xml |
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Log: |
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Adding draft vpnc howto from #97760 |
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Revision Changes Path |
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1.1 xml/htdocs/doc/en/draft/vpnc-howto.xml |
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file : http://www.gentoo.org/cgi-bin/viewcvs.cgi/xml/htdocs/doc/en/draft/vpnc-howto.xml?rev=1.1&content-type=text/x-cvsweb-markup&cvsroot=gentoo |
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plain: http://www.gentoo.org/cgi-bin/viewcvs.cgi/xml/htdocs/doc/en/draft/vpnc-howto.xml?rev=1.1&content-type=text/plain&cvsroot=gentoo |
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Index: vpnc-howto.xml |
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=================================================================== |
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<?xml version='1.0' encoding='UTF-8'?> |
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<!DOCTYPE guide SYSTEM "/dtd/guide.dtd"> |
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|
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<guide link="/doc/en/draft/vpnc-howto.xml"> |
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<title>Gentoo vpnc HOWTO</title> |
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|
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<author title="Author"> |
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David H. Askew |
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</author> |
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|
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<!-- |
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My email address is dhaskew on earthlink.net |
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--> |
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|
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<abstract> |
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This document details how to connect your workstation to a Cisco VPN |
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concentrator utilizing vpnc to manage the connection. |
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</abstract> |
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|
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<!-- The content of this document is licensed under the CC-BY-SA license --> |
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<!-- See http://creativecommons.org/licenses/by-sa/2.5 --> |
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<license/> |
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|
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<version>0.9</version> |
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<date>2005-08-01</date> |
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|
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<chapter> |
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<title>Introduction</title> |
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<section> |
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<body> |
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|
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<p> |
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If you're reading this, then you likely need to connect to your office network |
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from home or during travel. Many companies utilize Cisco 3000 VPN concentrators |
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for their VPN needs, and I am willing to bet that most Linux newbies think that |
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they are forced to use Windows to connect to them. Well this document informs |
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you that connecting to a Cisco VPN is very well be possible and will hopefully |
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enable to you to setup a working tunnel using your Gentoo workstation or laptop. |
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</p> |
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|
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</body> |
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</section> |
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<section> |
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<title>What this document is</title> |
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<body> |
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|
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<ul> |
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<li>A guide to the basic workings of vpnc</li> |
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<li>A discussion of DNS and routing issues that relate to VPNs</li> |
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<li>Examples of managing VPN sessions</li> |
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<li>Useful tips and tricks (hopefully)</li> |
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</ul> |
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|
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</body> |
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</section> |
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<section> |
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<title>What this document is not</title> |
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<body> |
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|
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<ul> |
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<li>An in-depth guide to VPN / encryption technologies</li> |
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<li>A feature by feature explanation of vpnc</li> |
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</ul> |
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|
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</body> |
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</section> |
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<section> |
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<title>Assumptions</title> |
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<body> |
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<p> |
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The assumptions made at this point are: |
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</p> |
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|
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<ul> |
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<li>You have Gentoo installed</li> |
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<li>You have Internet access</li> |
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<li>You want to connect to a Cisco 3000 VPN concentrator</li> |
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<li>You know how to configure, build and install a new kernel</li> |
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</ul> |
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</body> |
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</section> |
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</chapter> |
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|
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<chapter> |
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<title>Kernel Configuration</title> |
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<section> |
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<body> |
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|
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<p> |
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In order for Linux to be able to open a VPN connection <e>Universal TUN/TAP |
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device driver support</e> must be enabled in the kernel. What is it and why do |
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you need it? Below is a relatively straight forward explanation from the kernel |
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configuration dialog: |
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</p> |
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<pre caption="CONFIG_TUN:"> |
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TUN/TAP provides packet reception and transmission for user space |
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programs. It can be viewed as a simple Point-to-Point or Ethernet |
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device, which instead of receiving packets from a physical media, |
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receives them from user space program and instead of sending packets |
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via physical media writes them to the user space program. |
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When a program opens /dev/net/tun, driver creates and registers |
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corresponding net device tunX or tapX. After a program closed above |
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devices, driver will automatically delete tunXX or tapXX device and |
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all routes corresponding to it. |
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</pre> |
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<p> |
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You can verify if your kernel has TUN/TAP support with the following command: |
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</p> |
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<pre caption="Checking the kernel config"> |
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# <i>cat /usr/src/linux/.config | grep TUN</i> |
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CONFIG_INET_TUNNEL=m |
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# CONFIG_INET6_TUNNEL is not set |
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# CONFIG_IPV6_TUNNEL is not set |
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CONFIG_TUN=m |
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# CONFIG_8139TOO_TUNE_TWISTER is not set |
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</pre> |
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|
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<p> |
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As you can see above, <c>CONFIG_TUN=m</c> is compiled as a module. If it is |
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disabled in your setup, enable it in your kernel of choice, rebuild, |
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install, reboot and return to this document before continuing with the next |
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steps. |
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</p> |
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<pre caption="Configuration location in the kernel configuration dialog"> |
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Device Drivers ---> |
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Networking support ---> |
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[*] Universal TUN/TAP device driver support |
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</pre> |
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<p> |
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If you already have TUN/TAP support built in your kernel, or you just booted |
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your computer after a fresh kernel build, then you need to verify that the |
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kernel has the appropriate code initialized. |
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</p> |
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<p> |
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If you built TUN/TAP support directly into the kernel, you should see |
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information from <c>dmesg</c> output like the following: |
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</p> |
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|
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<pre caption="Checking dmesg output"> |
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# <i>dmesg | grep TUN</i> |
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Universal TUN/TAP device driver 1.5 (C)1999-2002 Maxim Krasnyansky |
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</pre> |
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<p> |
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If you build TUN/TAP support as a module, you first must load the <c>tun</c> |
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module: |
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</p> |
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|
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<pre caption="Load tun module"> |
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# <i>modprobe tun</i> |
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# <i>lsmod</i> |
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Module Size Used by |
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tun 7296 0 |
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nvidia 4050204 12 |
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</pre> |
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|
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<p> |
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Now that the <c>tun</c> module is loaded, check <c>dmesg</c> output. You |
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should see something like the following: |
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</p> |
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|
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<pre caption="Checking dmesg output"> |
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# <i>dmesg | grep TUN</i> |
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Universal TUN/TAP device driver 1.5 (C)1999-2002 Maxim Krasnyansky |
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</pre> |
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|
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</body> |
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</section> |
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</chapter> |
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<chapter> |
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<title>Install Needed Software</title> |
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<section> |
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<body> |
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<p> |
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Now that you have a working kernel setup, you need to install |
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<c>net-misc/vpnc</c>: |
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</p> |
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<pre caption="Installing vpnc"> |
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# <i>emerge net-misc/vpnc</i> |
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</pre> |
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</body> |
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</section> |
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</chapter> |
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-- |
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