DNS Flashcards
What is the primary purpose of DNS?
To translate domain names into IP addresses.
What are the main components of DNS?
DNS clients (resolvers), DNS servers, and DNS records.
What is a DNS resolver?
A DNS resolver is a client-side application that queries DNS servers to resolve domain names to IP addresses.
What is a DNS server?
A DNS server is a server that responds to DNS queries, providing the IP address associated with a domain name.
What are the types of DNS servers?
A: Recursive DNS servers, authoritative DNS servers, and root DNS servers.
What is a recursive DNS server?
A server that performs the complete process of resolving a domain name by querying multiple authoritative DNS servers if necessary.
What is an authoritative DNS server?
A server that holds the definitive records for a domain and responds to queries for that domain.
What is a root DNS server?
A server at the top of the DNS hierarchy that directs queries to appropriate top-level domain (TLD) servers.
What are DNS records?
Entries in a DNS database that provide information about a domain, including IP addresses and mail server addresses.
What is an A record?
An address record that maps a domain name to an IPv4 address.
What is an AAAA record?
An address record that maps a domain name to an IPv6 address.
What is a CNAME record?
A canonical name record that maps an alias name to a true (canonical) domain name.
What is an MX record?
A mail exchange record that specifies the mail server responsible for receiving email for a domain.
What is a PTR record?
A pointer record that maps an IP address to a domain name (reverse DNS lookup).
What is an NS record?
A name server record that indicates which DNS server is authoritative for a domain.
What is a TXT record?
A text record used to store text information, often for verification purposes.
What is a SOA record?
A start of authority record that provides information about the DNS zone and the authoritative DNS server for that zone.
What is a DNS zone?
A portion of the DNS namespace that is managed by a specific organization or administrator.
What is zone transfer in DNS?
The process of copying DNS zone data from a primary DNS server to a secondary DNS server.
What are the two types of zone transfers?
Full zone transfer (AXFR) and incremental zone transfer (IXFR).
What is DNS caching?
The temporary storage of DNS query results to reduce the load on DNS servers and improve response times.
What is TTL in DNS?
Time to Live; a value that specifies how long a DNS record should be cached before being discarded or refreshed.
What is a DNS query?
A request made by a DNS client to resolve a domain name to an IP address.
What is the difference between a forward lookup and a reverse lookup in DNS?
A forward lookup translates a domain name to an IP address, while a reverse lookup translates an IP address to a domain name.
What is DNSSEC?
DNS Security Extensions; a suite of specifications to secure information provided by DNS by ensuring its authenticity and integrity.
What is a FQDN?
Fully Qualified Domain Name; the complete domain name for a specific computer or host on the internet.
What is the function of the BIND software in DNS?
Berkeley Internet Name Domain (BIND) is the most widely used DNS software on the internet.
What is a split-horizon DNS?
A DNS configuration where two different DNS responses are provided for the same query based on the source of the query.
What is a Domain Registrar?
An organization that manages the reservation of domain names. Examples include GoDaddy, Namecheap, and Google Domains.
What is a Web Host?
A service provider that offers storage space and access for websites. Examples include Bluehost, SiteGround, and Vercel.
What is a Nameserver?
A server that handles queries about the location of a domain name’s services. It translates domain names into IP addresses.
Is a DNS resolver part of the browser?
No, a DNS resolver is not part of the browser. The browser initiates DNS queries, which are handled by the client-side stub resolver and then forwarded to a recursive DNS resolver to resolve domain names to IP addresses.
