Why does DNS work the way it does?

Posted by sabof on Server Fault See other posts from Server Fault or by sabof
Published on 2012-02-01T17:24:13Z Indexed on 2012/09/09 21:39 UTC
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canonical

This is a Canonical Question about DNS (Domain Name Service).

If my understanding of the DNS system is correct, the .com registry holds a table that maps domains (www.example.com) to DNS servers.

What is the advantage? Why not map directly to an IP address?
If the only record that needs to change when I am configuring a DNS server to point to a different IP address, is located at the DNS server, why isn't the process instant?
If the only reason for the delay are DNS caches, is it possible to bypass them, so I can see what is happening in real time?

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