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Techpaper Migration

General questions

What is IPv6?

IPv6 stands for Internet Protocol version 6 and is the successor of IPv4. The main difference between the two standards is the length of the IP addresses and, consequently, the number of IP addresses available. With IPv6 an IP address has 128 bits, while IPv4 has just 32 bits.

How long will IPv4 addresses continue to exist?

The transition to IPv6 is a long-term process (see Migration to IPv6. The distribution of IP addresses takes place in three steps: The IANA (Internet Assigned Numbers Authority) distributes IP address ranges to the five RIRs (Regional Internet Registries), who in turn distribute these to the individual LIRs (Local Internet Registries). Finally, the LIR distributes IP addresses to their customers. This means that where some LIRs may still have IPv4 addresses available, others can distribute IPv6 addresses only. The IANA assigned the last IPv4 addresses of the block /8 on January 31th, 2011, the APNIC (Asia Pacific Network Information Centre) on April 15th, 2011 and ARIN (American Registry for Internet Numbers) on April 23rd, 2014. For example RIPE NCC, the organization responsible for Germany, is likely to be the next RIR to run out of IPv4 addresses. It stresses, however, that the Internet will continue to function even if IPv4 addresses in this pool were to be exhausted (see RIPE NCC).

Existing customers such as companies that already have Internet connections and their own web sites have no reason to worry: The IPv6 Internet is growing slowly and there will almost always be a way to access it. Only for new customers, new providers and new websites could it occur that IPv4 addresses are no longer available. This situation is currently expected for emerging markets, and for Asia in particular.

Our company has an IPv4-only infrastructure – how can we access IPv6 web sites?

You can continue to access the Internet as normal with IPv4 and you remain fully available for your customers. To access the IPv6 Internet, for example, you can use services that map your IPv4 address to an IPv6 address. These services include proxies for IPv6 web sites, tunneling mechanisms such as 6to4, 6in4, or protocols such as Teredeo (Microsoft) or Miredo (Linux).

What does the transition from IPv4 to IPv6 mean for enterprises?

There will be no sudden switch from IPv4 to IPv6. The migration process is slow and the major stakeholders are currently working on the technical implementation. Both Internet protocols will coexist for a very long time, so a slow transition is viable. IPv4 is not due to be turned off for a very long time. What is certain, however, is that for the ongoing dynamic development of the Internet, IPv6 is an absolute necessity.

What considerations are there for the transition to IPv6?

Current client and server operating systems are IPv6 capable, but there are very few Internet providers already offering native IPv6 access. For this reason the current recommendation is to use the parallel operation of IPv6 and IPv4, whereby ISPs will assign both address types (known as dual stack) – this is already carried out by regional and bigger providers. The final step will be to operate the general overall infrastructure on the basis of IPv6 and to provide tunneling mechanisms to access IPv4 networks.

Which LANCOM network components are already IPv6-capable?

A detailed overview of which devices support what features is available here .

Technical questions

What is the purpose of the various different IP addresses with IPv6?

  • Link-local: Used to communicate over the local link and as the basis for auto-configuration to obtain a global unicast address.
  • Global unicast: This address is used for communication in the Internet; it is unique and public.

Can my device always be identified worldwide by the same IPv6 address?

No. Every terminal and client can be assigned with a global-unicast type unique IPv6 address. However, this address changes when the device enters a different network, i.e. when moving from the home network to the company network or mobile networks. Even terminals that remain in the same network also remain unidentifiable thanks to the privacy extensions. Each terminal regularly changes its interface identifier so that it is not identifiable by its MAC address. The privacy extensions are a function in the client.

Which major protocols operate differently with IPv6?

  • Broadcast: Not used; replaced by multicast.
  • ARP: Not used; replaced by Neighbor Discovery.
  • DHCP: Stateful auto-configuration works with DHCPv6, while stateless auto-configuration can do without. However, it is possible to use DHCPv6 for a stateless auto-configuration, for example for the specification of DNS servers and other options.
  • DNS: There is no such a thing as DNSv6. The existing DNS A records are merely supplemented by additional AAAA records for IPv6.
  • ICMP: ICMPv6 is used for the Neighbor Discovery and other functions.
  • NAT: NAT is generally not intended for IPv6.

What important innovations does IPv6 provide?

In addition to the expanded address space, IPv6 provides another important innovation. The Stateless Address Auto-Configuration (SLAAC) enables a client to use a prefix communicated by a router to generate its own IP address. Neighbor Discovery in IPv6 prevents the assignment of duplicate IP addresses.