2018-03-29 16:28:29 +07:00
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<meta charset="utf-8" emacsmode="-*- markdown -*-">
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**A warm welcome to DNS**
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# Resolver
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2018-03-30 03:36:26 +07:00
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Writing a modern resolver is the hardest part of DNS. A fully standards
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compliant DNS resolver is not a resolver that can be used in practice.
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In reality, resolvers are expected to process malformed queries coming from
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clients (stub-resolvers). Furthermore, many authoritative servers respond
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incorrectly to modern DNS queries. Zones are frequently misconfigured on
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authoritative servers but still expected to work correctly.
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Meanwhile, operators desire top performance, with individual CPU cores
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expected to satisfy the DNS needs of hundreds of thousands of users.
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To top this off, a modern DNS resolver will have to validate DNSSEC
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correctly. This may be among the hardest challenges of any widely used
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Internet protocol.
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So in short, before attempting to write a DNS resolver, ponder if you really
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need to.
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2018-03-29 16:28:29 +07:00
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2018-03-30 04:29:30 +07:00
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TBC..
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2018-03-30 20:50:32 +07:00
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