IPv6 day

Continuing the theme “With IPv6 World Day!” I, on behalf of the team
REG.RU, I want to emphasize important information about version 6 of the Internet Protocol and a little
analyze the situation. By the way, our company also participates in the global testing of IPv6 .

As you know, the usual IP addresses are rapidly ending. For example, for the Asian region, they no longer stand out at all. Europe still has several million in stock, but allocation takes place at a speed of 2 million addresses per week, i.e. Soon they will not be.

A curious fact: in version 6 the header checksum field was abolished, this was done due to the presence of integrity checks at the lower and higher levels.
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What will happen next?

We will have to switch to IPv6, whether we like it or not. The transition did not begin today or even yesterday, but a long “perestroika” period still awaits us. Let me remind you that IPv4 and IPv6 are not compatible protocols. Therefore, additional mechanisms are needed to ensure the interoperability of IPv4 and IPv6 nodes.

Everything is already invented!

As part of the IETF (The Internet Engineering Task Force), the NGTRANS (Next Generation Transition) working group was organized, the main goal of which is to specify the tools and mechanisms for solving the problems that have appeared.

There are two main problems:

“The first of these is related to the provision of IPv6 interoperability between IPv6“ islands ”separated by IPv4“ sea ”.

- The second problem is the organization of interaction between the existing world of IPv4 and the new world of IPv6.

Consider the most popular solutions:

6to4 tunnels are used to connect isolated IPv6 domains in the IPv4 world. The border router of an IPv6 domain creates a tunnel to another IPv6 domain. Tunnel endpoints are identified in the IPv6 domain prefix. This prefix is ​​formed from the unique prefix 6to4 / 16 plus the IPv4 address of the border router.

6over4 - allows you to connect IPv6 "islands", but without an explicit tunnel, IPv4 in this case acts as a transparent transport. You can do this for example through the protocol Teredo.

Directly interconnecting IPv6 networks with IPv4 is possible by implementing a dual stack model. In it, all IPv6 nodes, hosts or routers have a double stack, that is, they support the implementation of IPv4 and IPv6 protocols. Thus, communication with IPv4 nodes is done using the IPv4 stack, and communication with IPv6 nodes is done using the IPv6 stack. An obvious disadvantage is the need to assign new devices other than IPv6 addresses, also the usual IPv4, which are now almost nonexistent.

Therefore, we arrive at a bounded double stack model. In this model, only server nodes have a double stack. New "client nodes" work only over IPv6.

Summarizing, I will say that IPv6 is without a doubt a new round in the development of the global network, which once again shows its enormous growth, and this is great. But there is a drawback: the tasks of network administration and the development of services during the transition period must take into account the duality of the stack and all possible pitfalls.

I wish you all a good start working with IPv6. Let the IP never end!

Support material:
www.viagenie.qc.ca/en/ipv6/presentations/IPv6-transition-mechanisms_v1.pdf
www.ngnet.it/e/trans