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DNS resolvers have several advantages over letting each Internet host query directly nameservers. Firstly, regular Internet hosts do not need to maintain the up-to-date list of the addresses of the root servers. Secondly, regular Internet hosts do not need to send queries to nameservers all over the Internet. Furthermore, as a DNS resolver serves a large number of hosts, it can cache the received answers. This allows the resolver to quickly return answers for popular DNS queries and reduces the load on all DNS servers [JSBM2002]_.
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Benefits of names
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if the server process moves to another physical server, all clients must be informed about the new server address
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if there are many concurrent clients, the load of the server will increase without any possibility of adding another server without changing the server addresses used by the clients
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Footnotes
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The :term:`hosts.txt` file is not maintained anymore. A historical snapshot from April 1984 is available from http://ftp.univie.ac.at/netinfo/netinfo/hosts.txt
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See http://www.donelan.com/dnstimeline.html for a time line of DNS related developments.
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This specification evolved later to support domain names written by using other character sets than us-ASCII :rfc:`5890`. This extension is important to support languages other than English, but a detailed discussion is outside the scope of this document.
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The official list of top-level domain names is maintained by :term:`IANA` at http://data.iana.org/TLD/tlds-alpha-by-domain.txt Additional information about these domains may be found at http://en.wikipedia.org/wiki/List_of_Internet_top-level_domains
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A copy of the information maintained by each root nameserver is available at http://www.internic.net/zones/root.zone
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It is interesting to note that to prevent any homograph attack, Google Inc. registered the `g00gle.com` domain name but does not apparently use it.
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