[OneWingedShark]

DNS In A Nutshell
DNS connects browsers to servers by translating URLs into the IP (Internet Protocol) numbers that are used by routers and servers to direct HTTP requests and data to the right places.

There are two fundamental types of DNS servers that allow this to work: the servers that respond to browser’s queries and the servers that hold the canonical information about which IP maps to which URL.


Recursive DNS Servers
When your browser sends out a DNS query — assuming the browser doesn’t already have the mapping stored in its cache — it is sent to a recursive DNS server. Recursive servers are the part of the DNS that provides the required information to web clients. They are usually managed by ISPs or the organizations that own the domain from which the connection is being made — a company, for example, although there are some popular public recursive DNS servers run by big corporations like Google and other organizations.


Authoritative DNS Servers
Authoritative DNS servers “know” the mapping of URL to IP for a domain. They are the source of the information that the recursive DNS servers send to web clients like browsers. Authoritative DNS servers for a website are usually provided by web hosting companies or specialist DNS hosting companies.

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Thus, as DNS is so fundamental to the internet's structure, it is very good that there's now a formally verified implementation.

[OneWingedShark]

Could you do your tech ping?
Thank you.

[SecondAmendment]

Ada ... a very good programming language with less career potential than Cobol or Fortran.

[ShadowAce]

[rarestia]

Having implemented MSDNS, BIND, and Ironsides, I can tell you that Ironsides blows away the competition for security. DNS poisoning is impossible if configured by a competent admin.

That being said, Ironsides lacks a lot of the features available in MSDNS and a lot of the flexibility of BIND.