Root Nameservers

• Authoritative for root (ì.î) domain

• Responsible for COM, EDU, NET, ORG, and some other top-level domains, (especially) including IN-ADDR.ARPA. (this week)

• Point to the remainder of the top level domains: MIL, IE, US, DE, and all others.

• Not one of your nameservers

  • Unless you are not connected to the Internet

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All name resolution begins with the root nameservers

Root nameservers provide the answers to the top-level domains

Root nameservers are critical to the name resolution
if all nameservers were unavailable for an extended period of time, all name resolution on the Internet would fail

to protect against this, the Internet has multiple nameservers spread across different parts of the network

Nameserver queries come in two flavors:
recursive: places the bulk of the query process on a single nameserver to continue quering until it learns the answer

non-recursive (or iterative): the nameserver gives back the best answer that it already knows. This is less work

Root-nameservers are non-recursive and return answers pointing to the next domain level