A workstation on an enterprise network needs to establish a connection to an external host… — CompTIA Network+

A workstation on an enterprise network needs to establish a connection to an external host at $secure.partner.example.org$ . The workstation has no cached DNS entries for this domain. Place the operational steps of the standard recursive DNS resolution process in the correct chronological order from first to last.

1The client stub resolver checks its local cache and hosts file, then issues a recursive query to the configured local DNS resolver.
2The local DNS resolver sends an iterative query to a DNS Root Name Server ( $.$ ).
3The Root Name Server responds to the local resolver with a referral containing the NS records for the $.org$ Top-Level Domain (TLD) servers.
4The local DNS resolver sends an iterative query to the $.org$ TLD server and receives a referral to the authoritative name server for $example.org$ .
5The local DNS resolver queries the authoritative name server for $example.org$ , receives the Host IPv4 ( $A$ ) record for $secure.partner.example.org$ , and returns the answer to the client.

Answer

The correct sequence starts with the client stub resolver querying the local recursive resolver, followed by iterative queries from the recursive resolver to the Root Name Server, the TLD server, and finally the Authoritative Name Server to obtain the host A record.

The correct order follows the standard DNS lookup traversal: local client stub resolver initiation -> iterative query to Root server -> referral to TLD server -> referral to Authoritative server -> authoritative answer returned to client.

Step-by-Step Solution

Initiate query from client stub resolver

Local cache check fails; recursive query is sent to local DNS resolver.

Client applications rely on the configured local DNS server to handle full name resolution.

Query Root Name Server

Local resolver issues an iterative query over UDP port 53 to a DNS root server.

Root servers serve as the top level of the hierarchical DNS namespace tree.

Receive TLD referral

Root server refers local resolver to the name servers responsible for the target TLD.

Root servers direct traffic to TLD servers based on the root suffix of the request.

Query TLD Name Server

Local resolver queries the TLD server and receives referral NS records for the specific domain.

TLD servers maintain records for registered domain name delegations within their top-level domain.

Query Authoritative Name Server

Local resolver requests the host A record from the authoritative server, caches the response, and returns the IP to the client.

Authoritative servers contain the actual zone files containing resource records such as A, AAAA, or MX entries.

Key Concept

Iterative and Recursive DNS Resolution Hierarchy

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