DNS Record Types Flashcards
DNS (Domain Name System) records are used to map human-friendly domain names (like example.com) to IP addresses or other pieces of information. These records are stored in DNS servers and are crucial for the functioning of the internet. Different types of DNS records serve different purposes. Here’s an overview of the most common DNS record types.
A record
Maps a domain name to an IPv4 address
Example: If example.com has an A record of 192.0.2.1, when someone types example.com in their browser, the DNS translates it to the IP address 192.0.2.1 and connects them to that server.
AAAA record
Maps a domain name to an IPv6 address.
Example: If example.com has an AAAA record of 2001:0db8:85a3:0000:0000:8a2e:0370:7334, this record is used to connect users to an IPv6-enabled server.
CNAME Record
Canonical Name Record
Maps a domain name to another domain name (aliasing)
Example: If www.example.com has a CNAME record pointing to example.com, when someone accesses www.example.com, the DNS will redirect them to example.com.
MX Record
Mail Exchange Record
Specifies the mail servers responsible for receiving email for a domain
Example: If example.com has an MX record pointing to mail.example.com, all emails sent to @example.com addresses will be routed to mail.example.com
NS Record
Name Server Record
Indicates the authoritative DNS servers for the domain
Example: If example.com has NS records pointing to ns1.example.com and ns2.example.com, these servers are responsible for handling DNS queries for example.com.
PTR Record
Pointer Record
Maps an IP address to a domain name (reverse DNS lookup)
Example: If 192.0.2.1 has a PTR record pointing to example.com, a reverse DNS lookup for the IP address 192.0.2.1 would return example.com.
SRV Record
Service Record
Specifies the location (hostname and port) of servers for specific services.
Example: An SRV record might be used to specify the location of a service like a SIP server (_sip._tcp.example.com).
SOA Record
Start of Authority Record
Provides important information about the domain, such as the primary name server, the email of the domain administrator, and various timing settings
Example: The SOA record includes data like the refresh rate for the DNS zone and the contact email for the administrator
