Skip to main content

IPv6 Address Added for Root Servers in the Root Zone | Addition enhances end-to-end connectivity for IPv6 networks

MARINA DEL REY, Calif.: The Internet Corporation for Assigned Names and Numbers today took another step along the path of deployment for the next-generation IPv6 Internet addressing system.

IPv6 addresses were added for six of the world’s 13 root server networks (A, F, H, J, K, M) to the appropriate files and databases. This move allows for the possibility of fuller IPv6 usage of the Domain Name System (DNS). Prior to today, those using IPv6 had needed to retain the older IPv4 addressing system in order to be able to use domain names.

"The ISP community welcomes this development as part of the continuing evolution of the public Internet,” said Tony Holmes, chair of ICANN’s Internet Service and Connectivity Provider Constituency. “IPv6 will be an essential part our future and support in the root servers is essential to the growth, stability, and reliability of the public Internet.”

Name server software relies on the root servers as a key part in translating domains like “” into the routing identifiers used by computers to connect to one another. In 2007 the ICANN Security and Stability Advisory Committee concluded that ICANN should move forward with the enhancement of the DNS root service by adding IPv6 addresses for the root servers.

As more and more devices connect to the Internet they require unique Internet Protocol (IP) addresses. The remaining free pool of unassigned IPv4 addresses is being depleted by the growth of the Internet. IPv6 is the addressing protocol that increases the unique IP addresses from the 4 billion available in IPv4, to more than 340 trillion trillion trillion.

“Today’s addition of IPv6 addresses for the root servers enhances the end-to-end connectivity for IPv6 networks, and furthers the growth of the global interoperable Internet,” added David Conrad, ICANN’s Vice President of Research and IANA Strategy. “This is a major step forward for IPv6-only connectivity and the global migration to IPv6.”

Further technical information on the move is available at


About ICANN:

ICANN is responsible for the global coordination of the Internet's system of unique identifiers like domain names (like .org, .museum and country codes like .uk) and the addresses used in a variety of Internet protocols that help computers reach each other over the Internet. Careful management of these resources is vital to the Internet's operation, so ICANN's global stakeholders meet regularly to develop policies that ensure the Internet's ongoing security and stability. ICANN is an internationally organized, public benefit non-profit company. For more information please visit: .

About IANA:

The Internet Assigned Numbers Authority (IANA) is the body responsible for coordinating some of the key elements that keep the Internet running smoothly. Whilst the Internet is renowned for being a worldwide network free from central coordination, there is a technical need for some key parts of the Internet to be globally coordinated – and this coordination role is undertaken by IANA.

Media Contacts:

Jason Keenan
Media Adviser, ICANN
Ph: +1 310 382 4004

International: Andrew Robertson
Edelman ( London)
Ph: +44 7921 588 770

More Announcements
Domain Name System
Internationalized Domain Name ,IDN,"IDNs are domain names that include characters used in the local representation of languages that are not written with the twenty-six letters of the basic Latin alphabet ""a-z"". An IDN can contain Latin letters with diacritical marks, as required by many European languages, or may consist of characters from non-Latin scripts such as Arabic or Chinese. Many languages also use other types of digits than the European ""0-9"". The basic Latin alphabet together with the European-Arabic digits are, for the purpose of domain names, termed ""ASCII characters"" (ASCII = American Standard Code for Information Interchange). These are also included in the broader range of ""Unicode characters"" that provides the basis for IDNs. The ""hostname rule"" requires that all domain names of the type under consideration here are stored in the DNS using only the ASCII characters listed above, with the one further addition of the hyphen ""-"". The Unicode form of an IDN therefore requires special encoding before it is entered into the DNS. The following terminology is used when distinguishing between these forms: A domain name consists of a series of ""labels"" (separated by ""dots""). The ASCII form of an IDN label is termed an ""A-label"". All operations defined in the DNS protocol use A-labels exclusively. The Unicode form, which a user expects to be displayed, is termed a ""U-label"". The difference may be illustrated with the Hindi word for ""test"" — परीका — appearing here as a U-label would (in the Devanagari script). A special form of ""ASCII compatible encoding"" (abbreviated ACE) is applied to this to produce the corresponding A-label: xn--11b5bs1di. A domain name that only includes ASCII letters, digits, and hyphens is termed an ""LDH label"". Although the definitions of A-labels and LDH-labels overlap, a name consisting exclusively of LDH labels, such as"""" is not an IDN."