NAT-PT Install and Configuration

By Vasaka Visoottiviseth (ccvvs at mahidol dot ac dot th)

We use KAME's NAT-PT implemenation for FreeBSD 4.10 (kame-20041206-freebsd410-snap.tgz) that can be downloaded from "ftp.kame.net/pub/kame/snap/".

Installation of KAME snap-kit

• Decompress the snap-kit. This will create a directory named "kame".

  % tar xvzf kame-20041206-freebsd410-snap.tgz
  % cd kame

• Read the "INSTALL" file.
• Invoke the following command to create necessary symbolic links for building the kernel. The following example is assumed that you are using "FreeBSD Release 4.x". If you use NetBSD or FreeBSD 5, your target should be changed.

  % make TARGET=freebsd4 prepare

• Then, go to the directory freebsd4 inside.

  % cd freebsd4

• They will have another "INSTALL" file, read it.
• As from INSTALL file, as the root, Step 1 is to BACKUP your current kernel. (The following is for FreeBSD4.10)

  # cp /kernel /kernel.previous
  # cd /usr
  # mkdir include.clean
  # cd include.clean
  # (cd ../include; tar Bpcf - .) | tar Bpxf -

• Step 2 is Kernel Build. First rewrite your configuration file by using editor "vi". Delete the comment-out mark "#" from the line "#options NATPT".

  % cd kame/freebsd4/sys/i386/conf
  % cp GENERIC.KAME CONFIGFILE
  % vi CONFIGFILE

• Configure your CONFIGFILE.

  % config CONFIGFILE

• Build the kernel.

  % cd ../../compile/CONFIGFILE
  % make depend && make

• As the root, install the kernel.

  # make install

• Next to install userland tools, return to the directory "kame/freebsd4", and do as following.

  % make includes
  # make install-includes

  % make # make install

• All things are finished. You have to reboot the computer.

  # fastboot

• After the reboot, you can check your new kernel by the command:

  % uname -a

• Next, include the following line to your environment file or ".cshrc" file.

    PATH=/usr/local/v6/sbin:/usr/local/v6/bin:${PATH}
  

• To enable KAME's manunal via command "man", you have to include the following line to the file "/etc/manpath.config".

    OPTIONAL_MANPATH        	/usr/local/v6/man
  

IPv6 and NAT-PT Configuration

• Edit the "/etc/rc.conf" file like this. Change "xl0" to your network interface's name. "rtadvd" is the router advertisement daemon.

  ipv6_enable="YES"
  ipv6_network_interfaces="xl0"   
  ipv6_gateway_enable="YES"
  ipv6_prefix_xl0="3ffe:501:ffff:10"
  rtadvd_enable="YES"
  rtadvd_interfaces="xl0"
  

• Configure the "rtadvd". First, coppy the samle file.

  # cp /usr/local/v6/etc/rtadvd.conf.sample /etc/rtadvd.conf

• Read the manual file

  # man rtadvd.conf

• Rewrite the "/etc/rtadvd.conf" file somethings like in the rtadvd.conf's manual.

  default:\
    :chlim#64:raflags#0:rltime#1800:rtime#0:retrans#0:\
    :pinfoflags#192:vltime#2590000:pltime#604800:mtu#1500:
  xl0:\
    :addr="3ffe:501:ffff:10000::"prefixlen#64:tc=default:
  

• Next configure NAT-PT. First, copy the sample file.

  #cp kame/kame/kame/natptconfig/natpt.conf /etc/natpt.conf

• Rewrite the configuration as you want. You can see the manual.

  # man natptconfig

• See the following file also "natptconfig.usage".

  % cd kame/kame/kame/natptconfig
  % more natptconfig.usage
  

To use KAME's natptconfig

"Natptconfig" command is for configuring IPv6-to-IPv4 translator in the kernel.

• Invoke the command by indicating the location of configuration file.

  # natptconfig -f /etc/natpt.conf

• If you want to see the translation rules, use the following.

  # natptconfig show rules

• If you want to see the current status, use the following

  # natptconfig show xlate

• To invode natptconfig everytime you reboot your system, you have to add the following to "/etc/rc.local" file.

  if [ -f /usr/local/v6/sbin/natptconfig]; then
  	/usr/local/v6/sbin/natptconfig -f /etc/natpt.conf
  	echo "Start natptconfig"
  fi
  

To use KAME's natptlog

"Natptlog" command is for monitoring logged packets.

• To run natptlog as the daemon:

  # natptlog -b

• To run natptlog in the debug mode:

  # natptlog -d [debuglevel]

• To invode natptlog everytime you reboot your system, you have to add the following to "/etc/rc.local" file.

  if [ -f /usr/local/v6/sbin/natptlog]; then
  	/usr/local/v6/sbin/natptlog -b
  	echo "Start natptlog"
  fi
  

Setting Log file for "natptlog"

• Edit the syslogd configuration file called "/etc/syslog.conf". Add the following 2 lines to this file.

  !natptlog
  *.*					/usr/home/vasaka/natptlog.txt
  

  Here, we suppose our log file is "/usr/home/vasaka/natptlog.txt". You can change whereever you want, for example, in the directory /var/log
  
• Prepare the file by using command "touch".

  % touch  /usr/home/vasaka/natptlog.txt
  

References