IPv6 is the new version of the Internet Protocol. It should replace progressively the current IPv4 routing protocol which is responsible for interconnecting the gateways of the thousands of networks across the worldwide Internet.

IPv6 was primarily designed to extend the current address space which has become too small to accomodate the increasing growth of the network. IPv6 addresses are 128-bit long, thus multiplying the potential Internet size by a factor of 2⁹⁶. This allows for different addressing schemes, new types of applications, etc...

IPv6 specifications have also been tuned to support the following:

• Plug-and-play configuration
• Efficient packet handling/routing
• End-to-end flow identification for integrated service
• Standard security mechanisms
• Mobility
• Smooth IPv4-to-IPv6 transition.

IPv6-DRET has been implemented inside the Linux operating system. The current release is based on kernel 2.1.6. Regular upgrades will keep up with the ever growing contribution to the Linux system.

Since routing issues are among the most important research interests concerning IPv6, our network stack is intended to accomodate both host and router IPv6 machines. Routing neighbor discovery daemons insure that host and routers on a same link are communicating properly to exchange parameters, set default routes, etc...

Besides implementing the router specification of the IPv6 protocol, a great deal of effort was also put into the developpement of RIPng into GateD.

As of today, the IPv6-DRET implementation makes it possible to start studying issues such as the impact of IPv6 mechanisms on multimedia applications transmission for example.

Current IPv6-DRET features

• IPv6 addressing
• Loopback, (multiple) ethernet interfaces
• IPv6 raw protocol
• ICMPv6 including error and ND messages
• Neighbor discovery
• IPv6 multicast
• UDP over IPv6
• Simple Interface Transition device
• IPv6 BSD API including most of R.Stevens' advanced APIs.
• IPv6 router
• Simple IPv6 forwarding
• Use of router advertisements

Future functionalities and features

• Extension headers
• IPv6 over ATM
• Performance tuning
• IPSEC capabilities

Applications currently available are network configuration (ifconfig, route) and debugging tools (ping,traceroute). Their use is described with more detail in the "How To".

Basically, ifconfig allows to configure IPv6 interface addresses for the loopback, SIT and Ethernet devices. By configuring, we mean add, delete addresses, set flags, etc... It can also be used to setup configured tunnels to remote IPv4/IPv6 routers across the IPv4 internet. section.

Route is used to configure IPv4 and IPv6 routes: add, delete routes, set flags, lookup the routing table, etc...
Actually, the use of the above tools is not really required for IPv6-DRET hosts when they are running the ndpd-host daemon and routers are running the ndpd-router daemon.

Ping is a useful tool to check if the route between two hosts of the Internet is up. Besides, it provides statistics such as the round-trip time, time-to-live, ... Traceroute, as its name indicates, traces the route between two hosts and reports the routers messages go through to reach a given machine.

This HOW TO provides information concerning the general setup of the package available by FTP on the WWW, and the configuration of IPv6-DRET hosts and routers.

Setting the package up

The kernel

• Issue the "make config" command in the Linux directory and setup the kernel defines according to your machine configuration.
• Enable IPv6 and Netlink capabilities:
  • CONFIG_NET_IPV6_DIM
  • CONFIG_NETLINK
  • CONFIG_RTNETLINK
  • CONFIG_IPV6_FORWARD for a router.
• Complete the kernel compilation:
  > make dep; make clean; make zImage
  Install the kernel and reboot.
• Modify the "/etc/protocols" file by adding the line:
  icmp6 58 ICMP6 # IPv6: ICMPv6
• If it does not already exist, create the /dev/route file:
  > mknod /dev/route c 36 0
  The ndp daemons listen on this file to learn devices/routes update from the kernel

DNS and resolver library