Objective 1.04 Explain the Dataflow of the DNS Query Process [iterative, Recursive, Lame Delegation, Host File, and Resolvers] 302 Practice Questions (Page 1)

Questions 1–5

1. 1application · medium

   A network administrator is comparing the load on DNS servers. The company uses a recursive resolver for internal clients and an authoritative server for its public zone. Which statement accurately describes the query load distribution?

   • ABoth servers bear an equal load because they both query external servers.
   • BThe authoritative server bears the load of following referrals, while the recursive resolver only answers queries for its own zone.
   • CThe recursive resolver bears the load of following referrals, while the authoritative server only answers queries for its own zone.
   • DThe recursive resolver only queries the authoritative server, so the load is minimal.
   Reveal Solution Discussion Select an answer first
2. 2foundation · easy

   Which statement is true about an iterative DNS query?

   • AThe DNS server always returns the authoritative answer directly
   • BThe DNS server returns a referral to the client, and the client is responsible for querying the referred server
   • CThe DNS server queries the root server, then the TLD server, then the authoritative server
   • DThe DNS server caches the final answer and returns it to the client
   Reveal Solution Discussion Select an answer first
4. 3expert · hard

   A network administrator is troubleshooting a DNS resolution issue. A client sends a query to the BIG-IP DNS, which is configured as a recursive resolver. The resolver has no cached data for the query. The resolver sends a query to the root server and receives a referral to the .com TLD servers. The resolver then sends a query to a .com TLD server and receives a referral to the example.com authoritative servers. The resolver then sends a query to the example.com authoritative server and receives the answer. Which statement best describes the process?

   • AThe resolver returned a referral to the client.
   • BThe resolver performed recursive resolution, querying each server in the hierarchy in sequence.
   • CThe resolver performed a single query to the authoritative server.
   • DThe resolver performed iterative resolution, querying each server in the hierarchy in sequence.
   Reveal Solution Discussion Select an answer first
5. 4expert · hard

   A network administrator is comparing the query load on two DNS servers. Server A is a recursive resolver. Server B is an authoritative-only server. Which statement accurately describes the query load on each server?

   • AServer B bears the load of following referrals, while Server A only answers queries for its own zone.
   • BServer A bears the load of following referrals, while Server B only answers queries for its own zone.
   • CServer A only queries Server B, so the load is minimal.
   • DBoth servers bear an equal load because they both query external servers.
   Reveal Solution Discussion Select an answer first
6. 5application · medium

   A small company has a single BIG-IP DNS system that serves as the recursive resolver for all internal clients. The administrator notices that the resolver is handling a high volume of queries and wants to reduce the load on the upstream ISP resolver. Which configuration change would most effectively reduce the number of queries sent upstream?

   • AConfigure the BIG-IP DNS to use iterative resolution instead of forwarding.
   • BReduce the cache size on the BIG-IP DNS.
   • CIncrease the TTL values on the internal authoritative zone records.
   • DEnable aggressive caching (RFC 8767) on the BIG-IP DNS.
   Reveal Solution Discussion Select an answer first