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A Root with a view…

Running a DNS server that serves the root gives an interesting view into the world of the DNS.With the ongoing improvements to the ICANN operated L-ROOT we’ve been fortunate enough to be able to make use of the “DNS Statistics Collector” tool.

http://dns.measurement-factory.com/tools/dsc/

“DSC” allows us to generate different views of the DNS queries we have been seeing at the L-ROOT systems. Both to the current IP address (199.7.83.42) and to the old address (198.32.64.12).

  • The above graph shows the commonly queried Top Level Domains for a single day and the type of queries being asked. These are queries seen across l.root-servers.net. The TLDs change from day to day but some are persistent.No surprises in there really although some of the TLDs being queried should raise a few eyebrows.Seeing mainly addresses record queries (A and AAAA) for .com or .net, or a lot of requests for reverse delegation informations (PTR) in .arpa are logical things to see.However, “.local” is constantly in the top five of queries which is likely an indication of misconfiguration somewhere. Regular appearances are also made by “.localhost”, “.belkin”, “.home”, “.invalid”, “.localdomain” and “.domain”.I leave it to the reader to decide why this is and at whom to point fingers…

    Clearly one thing is certain, a large portion of the queries we are seeing are for non existing domains and hence get answered with “NXDOMAIN” (See above).Oh and one last snippet of information. I know that sometimes people do not allow DNS queries over TCP. This is actually not a good idea. According to the RFCs it is OK to query over TCP and in the case of a large enough answer (over 512 bytes) then TCP is typically the way to get that. So although the number of TCP queries is small compared to those using UDP, they can be valid queries.

    Special thanks have to go to the folks who produced DSC . If only for making my life easier.If people want to see more data or would like to hear more about what we are doing in L-ROOT operations then speak up and I will do my best to inform. After all we run this for the community.Also see http://l.root-servers.org for information on L-ROOT operations

  • Comments

      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""icann.org"" is not an IDN."