DNS Queries

Recursive query

• Delegate the lookup to a DNS Server
  • The DNS Serveer does the work adn reports back
    • 
• Large DNS cache provides a speed advatage

Iterative queries

• Do all queries ==yourself==
  • 
• Your DNS cache is specyfic to ure device
  1 ### TTL Time to live
• Configured on the authoritative server
• Specyfie how long cache is valid >[!bug]- >A very long TTL can cause problems if changes are made

2

Answers >[!example]- nslookup

answers >

The Authority The DNS server is the authority for the zone

Non-authoraitve

• Does not cotain the zone source files
  • Propably casched information

3

Lookups dig_command

Forword Lookup

• Provide the DNS server with FQDN
• DNS server provides an IP addres

Reverse DNS lookup

• Provides the DNS server with an IP addres
• DNS server provides an FQDN >[!example]- >

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DNS DNS_Records