Why you want IPv6

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You need IPv6. You just don't know it yet. Find out how to get it, how to benefit from it and how it will increase your shareholder value.

What is IPv6, and why would I care?

Internet is built upon a protocol suite called TCP/IP. This abbreviation stands for Transmission Control Protocol, and Internet Protocol.

When your computer communicates with the Internet a unique IP address is used to transfer and receive information. Yesterdays IP standard is called IPv4. Sadly most ISPs and services still only deliver this ancient technology standarized in September 1981. What you will want after reading on is IPv6, also referred to as IP Next Generation (IPNG).

Background: The IP shortage

IP version 4 defines a 32-bit address. This means there are 2^32 (4,294,967,296) unique IPv4 adresses available. This may sound like a big number. It is not, most of them are already tied up and the Internet is simply running out of IPs.

The address shortage problem is aggravated by the fact that portions of the IP address space have not been efficiently allocated.

The wall: Network Address Translation (NAT)

A technology called NAT or Network Address Translation is widely implemented to temporarily solve the IP address shortage and is commonly used to provide additional network security. A NAT firewall is placed between the real Internet and local area networks. NAT allows computers on the local network to connect with the outside world, but because the machines on the local network do not have their own Internet IPs they can not be directly accessed from the outside.

Some Very Huge numbers

Compare the numbers.. ..and realize why IPv6 is great:

  • Total number of IPv4 IP Addresses: 4,294,967,296
  • Number of IP Addresses in a IPv6 /64 prefix, the typical space a home user gets: 18,446,744,073,709,551,616

IPv6 gives citizens the opportunity to become real Internet participants. IPv4 makes citizens into passive consumers who are only able to connect to compartmentalized networks run by companies or governments. This is why the establishment does not want IPv6.

There is a total of 2^128, or 340,282,366,920,938,463,463,374,607,431,768,211,456 unique IPv6 adresses. That's roughly 667 quadrillion addresses per square millimeter of the Earth's surface!

Who uses IPv6 today, how widespread is it?

Linuxreviews project had 642074 unique visitors using IPv4 and 555 using IPv6 in June 2004.

According to these numbers less than a percent (0.086%) of the Internet browsers are IPv6 ready.

Truly hardcore 1337 Nerds are the only ones who use IPv6 today.

Understanding IPv6 addresses

IPv6 IPs have **8** notations of **4** hex numbers (0-f). May look like

  • 2001:0DB8:400:965a:0000:0000:0000:0001 and
  • 2001:0DB8:400:965a::1 (different ways of stating the same address).

:: is used to short down IP addresses. :: means that the space in between is filled by zeros and can only be used once in an address.

  • 2001:0DB8:400:965a:: is short for
  • 2001:0DB8:400:965a:0000:0000:0000:0000
  • 2001:0DB8:400:965a:0042::1 is short for
  • 2001:0DB8:400:965a:0042:0000:0000:0001

You can strip leading zeros, 2001:0DB8:400:965a:0042::1 becomes 2001:DB8:400:965a:42::1.

Know your prefix

| Prefix |   Number of IPv6 IPs                       | Space                         |
|  127   |   2                                        | none                          |
|  120   |   256                                      | xx                            | 
|   64   |   18,446,744,073,709,551,616               | xxxx:xxxx:xxxx:xxxx           |   
|   48   |   1,208,925,819,614,629,174,706,176        | xxxx:xxxx:xxxx:xxxx:xxxx      |
|   32   |   79,228,162,514,264,337,593,543,950,336   | xxxx:xxxx:xxxx:xxxx:xxxx:xxxx |

Allocation means the address space available for subnets and more IPs. If you have a /127 address you can only connect one box to the IPv6 interface, with a /48 you can connect "all the devices in the world" using the allocation.

If your prefix is 2001:0DB8:0400::/48 then you are assigned all space beginning with 2001:0DB8:0400. You can use the space 2001:0DB8:0400:xxxx:xxxx:xxxx:xxxx:xxxx.

To organize yourself 2001:0DB8:0400::/48 can be divided into the subnets

  • 2001:0DB8:0400:000e::/64
  • 2001:0DB8:0400:000f::/64

Subnet Matrix Table

      ||| |||| |||| |||| |||| |||| ||||
      ||| |||| |||| |||| |||| |||| |||128
      ||| |||| |||| |||| |||| |||| ||124
      ||| |||| |||| |||| |||| |||| |120
      ||| |||| |||| |||| |||| |||| 116
      ||| |||| |||| |||| |||| |||112
      ||| |||| |||| |||| |||| ||108
      ||| |||| |||| |||| |||| |104
      ||| |||| |||| |||| |||| 100
      ||| |||| |||| |||| |||96
      ||| |||| |||| |||| ||92
      ||| |||| |||| |||| |88
      ||| |||| |||| |||| 84
      ||| |||| |||| |||80
      ||| |||| |||| ||76
      ||| |||| |||| |72
      ||| |||| |||| 68
      ||| |||| |||64
      ||| |||| ||60
      ||| |||| |56
      ||| |||| 52
      ||| |||48
      ||| ||44
      ||| |40
      ||| 36

Get IPv6 NOW: Free IPv4 to IPv6 Tunnel Brokers

You should ping all the tunnelbrokers' POPs (points of presence) to determine the one closest to you.

See Free IPv4 to IPv6 Tunnel Brokers to find a tunnel broker near you.

Check ipv6tb: an implementation of the IPv6 Tunnel Broker for BSD software if you already have IPv6 and want to become a broker yourself.

The Standard way of setting up a IPv6 tunnel

First, make sure your firewall (if any) is not blocking protocol 41!


  • ipchains -I input -j ACCEPT --proto 41


  • iptables -A INPUT -p 41 -j ACCEPT

Example for a tunnel through http://tunnel-broker.singnet.com.sg/

ip tunnel add singnet mode sit remote ttl 255
ip link set singnet up                
ip -6 addr  add 2001:0DB8:ffff:5b::cf/127 dev singnet 
ip -6 route add 2001:0DB8:ffff:5b::ce/127 dev singnet 
ip -6 addr  add 2001:0DB8:ffff:5b::ce/127 dev eth1

And if you ever want to remove it:

iptunnel show
iptunnel del singnet
ip -6 addr  del 2001:0DB8:ffff:5b::cf/127 dev singnet 
ip -6 addr  del 2001:0DB8:ffff:5b::ce/127 dev eth1
ip -6 route del default dev singnet
  • NOTE: default is ignored when
    • ipv6_forwarding = enabled on Linux Kernel version < 2.4.21.
  • You must use 2000::/3 instead of default when
    • forwarding is enabled on a < 2.4.21 Linux Kernel. Many RedHat boxes "out there" use older kernels where you must use 2000::/3.

When IPv6 is up and running on your router you should use radvd, Linux IPv6 Router Advertisement Daemon, to automatically add and configure your LAN network.

How and why IPv6 can make your life more glamorous, your job easier to do and significantly increase your shareholder value

Having a truckload of IPs makes a lot of things much simpler. You can give each service running a IP of its own. More importantly, each device connected gets a unique IP.

You can use radvd and other tools to advertise IPv6 routes so they are configured automatically.

Generally IPv6 is smooth because you can use programs like gnomemeeting without worrying about NAT if you do not have a real IPv4 adress.

Totally Unimportant

Rumours say there is a significant amount of publicly open IPv6-only ftp and websites with content generally unavailable or hard to get on the old net. Using such services, if they do exist, may or may not be illegal. Such locations should never be exposed to the open, only shared with trusted friends. These sites usually only have one folder like /incoming or /upload where everyone can read and write as they please.

Radio stations

There is no real reason to use IPv6 for your radio unless you have native IPv6, Most IPv6 streams are relayed from IPv4, and the original ipv4 stream is usually a better choice.

IPv6 - The Next Network Protocol

Free open newsservers

Free alt.binaries.* is one of the great IPv6 attractions. That is why of course all links below are dead.

newszilla6.xs4all.nl          | Xs4all
news.ipv6.scarlet-internet.nl | Scarlet
news.ipv6.estpak.ee           | Elion

Visiting IPv4 sites through IPv6 - "Anonymous" web surfing until 2016

I was amazed to find that SixXS offered until 2016 a IPv6 to IPv4 Website Gateway that was free and open to everyone. All you needed to do before 2016 was adding .sixxs.org at the end of the website you had wanted to surf anonymously (or not: the original IP address had been forwarded to the visited site in the IP headers).

http://www.google.com.sixxs.org   | http://www.google.com   | Google
http://www.slashdot.org.sixxs.org | http://www.slashdot.org | Slashdot

Please only use this service in order to be anonymous or to visit IPv4 only sites if you don't have IPv4 support -- if they experience abuse they will probably close down this excellent service.

"The real (your) client IP is given in the X-Forwarded-For HTTP header just like normal gateways/proxies."

Internet Time Servers

Internet Relay Chat

IPv6 is great for shell (i.e. "bash" CLI) providers and IRC-bouncer users because a single /64 prefix gives you "unlimited" vhosts. Many irc servers k-line ( = block your IP) for off-partyline DNS such as I.do.not.buy.into.the.covid19.hoax.org. Also know that some servers only allow one connection from each IP, and some servers limit the number of connections from a /64. If you have a /48 then you should divide 10-20 IPs on separate /64s . Having 1000 shell users all using IRC on the same /64s is a bad idea.

Check the separate list of IPv6 supported IRC servers.

Links to more IPv6 fun

The major responsibilities of using IPv6

You must have a firewall and complete control of the services when you are in a IPv6 environment. Every computer is a equal node on the Internet. Where the NAT firewall stops all unestablished connections from the outside IPv6 welcomes it.

Many services, like xinetd, must have a configuration option enabled before they listen for ipv6 requests. But not all. As with IPv4 you should have complete control of what you are running, and a firewall protecting you against script kiddies.

Dead links to pages with tools that may have helped you on your way

most links below are dead by year 2020.

Is IPv6 working?

IPv6 Traceroute services

Where And What you can read about IPv6




Chinese Linux Documentation Project

Notes for Solaris users

Solaris uses the file /etc/inet/ipnodes for IPv6 hosts, the file /etc/hosts can not contain IPv6 hosts on Solaris systems. A peculiar issue is that /etc/inet/ipnodes can be used for IPv4 hosts too, but it can ONLY contain a IPv4 host OR ipv6 a host for a given domain. This mean that you should place your IPv6 hosts in /etc/inet/ipnodes and your IPv4 hosts in /etc/hosts if you are using both IPv4 and ipv6 on a Solaris system.


How to get it

How to configure it

IPv6 services