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Attention Network Operators and ISPs: Determine your readiness for the Root Zone KSK Rollover!

Network operators and Internet Service Providers (ISPs) still have time to test their recursive resolvers to make certain they are ready for the pending change of the cryptographic keys that help protect the Domain Name System (DNS).

Operators can use a testbed deployed by ICANN to confirm that their resolvers that have DNSSEC validation enabled will properly follow the upcoming Root Zone Domain Name Systems Security Extensions (DNSSEC) Key Signing Key (KSK) Rollover.

ICANN launched a testing platform in March 2017 that is specifically designed to allow network operators and other interested parties to confirm that their systems can handle the automated trust anchor update process for the Root Zone KSK Rollover.

To participate in the testing, network operators and ISPs join a mailing list that tells them what steps to take and when to perform these tests. It is possible to join at any point but the entire test takes about 45 days, with the most important results available about 30 days after the test begins.

Because the KSK Rollover is scheduled for 11 October 2017, we are encouraging operators of recursive resolvers with DNSSEC validation enabled to ensure that their systems are updated with the new root zone KSK configured as a trust anchor. If those systems do not support the automated trust anchor update protocol or do not implement it correctly, the trust anchor must be configured manually. If a recursive resolver's trust anchor is not updated, DNS resolution will fail for all clients using that recursive resolver causing any lookup to return a "host not found" or similar error message.

ICANN has published instructions for checking the configurations of popular recursive resolver implementations to determine if the new root zone KSK is properly configured as a trust anchor.

ICANN has also published instructions for configuring the most popular recursive resolver implementations to use the automated trust anchor protocol to stay updated with the latest root zone KSK.

You can learn more about the Root Zone KSK Rollover by visiting our webpage here. You can also access the testbed page here or ask questions about it at


    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."