DNS Flashcards
What are DNS record types?
DNS record types are different kinds of data entries in a DNS database that provide specific information about a domain, such as its IP address, mail servers, and other resources
What is the difference between an A record and an AAAA record?
A Record: Maps a domain name to an IPv4 address.
AAAA Record: Maps a domain name to an IPv6 address.
What is a CNAME record?
A CNAME (Canonical Name) record maps an alias name to the true or canonical domain name, essentially redirecting one domain name to another.
What is an MX record?
An MX (Mail Exchange) record specifies the mail servers responsible for receiving email for a domain, including their priority.
What is an SOA record?
An SOA (Start of Authority) record provides important information about a DNS zone, including the primary name server, the administrator’s email, the zone’s serial number, and timers for zone transfers.
What is a PTR record?
A PTR (Pointer) record maps an IP address to a domain name, used mainly for reverse DNS lookups to verify the IP address’ associated domain name.
What is a TXT record?
A TXT (Text) record allows the insertion of arbitrary text into DNS, commonly used for email validation (e.g., SPF, DKIM) and other verification purposes.
What is an SRV record?
An SRV (Service) record defines the location (hostname and port) of servers for specific services, used to direct traffic to appropriate servers.
What is an NS record?
An NS (Name Server) record specifies which DNS servers are authoritative for a particular zone, helping direct queries to the correct servers.
What is the global hierarchy in DNS?
The global hierarchy in DNS is the structured organization of DNS servers, starting from the root servers, followed by top-level domain (TLD) servers, and then authoritative servers for individual domains, ensuring a scalable and distributed system.
What are root DNS servers?
Root DNS servers are the top level in the DNS hierarchy, responsible for directing queries to the appropriate top-level domain (TLD) servers.
What is the difference between internal and external DNS?
internal DNS: Resolves hostnames within a private network.
External DNS: Resolves public domain names on the internet.
What are zone transfers in DNS?
Zone transfers are the process of copying DNS zone data from a primary DNS server to a secondary DNS server, ensuring consistency and redundancy.
What are authoritative name servers?
Authoritative name servers are DNS servers that hold the definitive records for a domain and can provide accurate responses to DNS queries for that domain.
What is Time to Live (TTL) in DNS?
TTL (Time to Live) is the duration in seconds that a DNS record is cached by DNS resolvers before it is refreshed. It helps manage how long DNS information is considered valid.
