DNS records are significant for the Domain Name System (DNS). They are instructions containing information about a domain with its associated IP address. There are also instructions about how to handle requests for that domain.
DNS records are stored in authoritative DNS servers and help translate human-readable domain names into machine-readable IP addresses. They help users to access websites and other online resources seamlessly.
The human-readable hostname contains a string of words that are easily memorable. IP addresses (IPV4) are numbers separated by dots, which are hard to remember. For example, geekflare.com is the human-readable hostname or domain name, while 172.66.43.88 is the current IP address for geekflare.com. An IP address related to a domain name may change based on the server on which the website is hosted.
Understanding the Structure of a DNS Record
A DNS record comprises several components with each serving a specific purpose:
- Name: This field is the domain or subdomain to which the DNS record applies. For instance, ‘example.com’ or ‘www.example.com’.
- TTL (Time to Live): TTL is the duration (in seconds) in which DNS resolvers should cache the record before fetching a fresh copy. A TTL of, 3600 means the record is cached for one hour.
- Class: It is the protocol family. The most commonly used class is ‘IN’, the Internet.
- Type: It is the type of DNS record, such as ‘A’, ‘MX’, ‘CNAME’, etc., each defining a different aspect of domain information.
- Data: It represents the information relevant to the record type. For example, in an ‘A’ record, the data field contains the IPv4 address while the MX record contains the hostname.
Common Types of DNS Records
The following are the common types of DNS records:
1. A Record
The A record is the most important DNS record type, pointing the domain or subdomain to an IP address. The “A” in A record stands for “address.” An A record indicates the IP address for a specific hostname or domain.
For example, you can use it for blog.website.com and point it to your blog. This is commonly used for eBay, Amazon, Tumblr, etc.
2. AAAA Record
Similar to an A record, an AAAA record points to the IP address for a domain. The difference between these two records is that they point to IPV6 addresses.
IPV6 is more advanced than IPV4 as it offers more IP addresses. With IPV6, you will never run out of unique IP addresses.
AAAA records help to resolve a domain name to the IPV6 protocol address.
3. CNAME Record
CNAME or Canonical Name is a DNS record that points a domain name to another domain. The alias points to the canonical name instead of an IP address in this record. For example, with CNAME the subdomain blog.example.com can point to example.com.
You can point a CNAME to another CNAME, but this is considered inefficient and can lead to slow load speed and poor user experience.
4. NS Record
An NS Record or Nameserver Record represents the authoritative DNS server for a domain.
The NS record enables pointing a domain name to its authoritative DNS servers assigned to the DNS zone. You can ensure the domain name is registered and configured correctly with an NS record.
After purchasing a web hosting service or setting up your website, you receive the details of the name server.
5. MX Record
An MX or mail exchange record is a DNS record showing the location of routing emails for a domain. It helps to direct emails to a mail server.
A MX record lets you hand off emails to a dedicated server. It means you can leave the work of setting up webmail on your server to an email provider. This offers custom email clients for reading and sending emails, enhanced security, and filters for spam.
Other Types of DNS Records
1. TXT Records
The TXT records allow domain administrators to store text notes in the record. These records are commonly used for domain ownership verification and implementing email security measures like SPF, DKIM, and DMARC.
2. SOA Record
State of Authority or SOA record saves authoritative information about a DNS zone, including the primary name server, the domain administrator’s email, the domain’s serial number, and timers related to zone refreshing.
3. SPF Record
A sender policy framework or SPF record is a type of TXT record that identifies the mail servers that are permitted to send email on behalf of a domain, helping to prevent email spoofing.
4. SRV Record
SRV or service records identify the location of servers for specific services, including the hostname and port number. Commonly used in configuring services like Microsoft Exchange and SIP.
5. Web Redirect Record
A Web Redirect or WR record redirects web traffic from one domain to another. It is helpful for redirecting traffic without changing the URL displayed to users.
6. ALIAS Record
ALIAS record allows a domain to point to another domain or hostname, similar to a CNAME record, but at the root domain level. It helps point the apex domain to a load balancer or another service.
7. RP Record
A Responsible Person or RP record provides information about the person responsible for a particular host or domain, including an email address and a pointer to a TXT record with additional information.
8. SSHFP Record
SSHFRP record or SSH Fingerprint record stores the SSH public key fingerprints, allowing SSH clients to verify the authenticity of the host’s key, enhancing security.
9. PTR Record
The Pointer record or PTR record is used for reverse DNS lookups, mapping an IP address to its corresponding domain name, essential for verifying the legitimacy of an IP address.
10. NAPTR Record
The Naming Authority Pointer or NAPTR record maps servers and users’ addresses in Session Initiation Protocol (SIP) with the help of IP telephony.
11. CAA Record
The CAA or Certification Authority Authorization record identifies which certificate authorities (CAs) are allowed to issue SSL/TLS certificates for a domain. It enhances security by preventing unauthorized certificate issuance.
12. Wildcard DNS Record
Wildcard DNS record matches requests for non-existent domain names. It allows administrators to direct traffic for undefined subdomains to a specific resource.
13. CERT Record
CERT record or certificate record stores certificates and related certificate revocation lists (CRLs) in the DNS. It is used to store PKIX, SPKI, PGP, and other types of certificates.
14. NSEC Record
Next, a Secure or NSEC record is used in DNSSEC to prove the non-existence of a DNS record, enhancing the security of the DNS infrastructure.
15. URLFWD Record
URLFWD or URL forwarding record enables users to access one web page via multiple URLs. Those using NS1 Connect can easily set up URL forwarding (HTTP redirects or masking) between zones. The three types of URL redirects used are masking, permanent (301), or temporary (302).
16. APL Record
APL or Address Prefix List record provides lists of address ranges for more efficient routing and access control.
17. AFSDB Record
Andrew File System Database or AFSDB record shows the location of AFS (Andrew File System) cell database servers, facilitating distributed file system operations.
18. DNSKEY Record
DNSKEY or DNS key record contains the public key used to verify DNSSEC signatures, ensuring the authenticity and integrity of DNS data.
19. CDNSKEY Record
CDNSKEY or Child DNS Key record is similar to DNSKEY but specifically used in child zones
20. DCHID Record
The DCHID record saves information for Dynamic Host Configuration Protocol (DHCP). DHCP is a standardized network protocol used on IP networks.
21. HIP Record
The HIP record or Host Identity Protocol associates a domain name with a Host Identity Tag. The Host Identity Tag is used in HIP to separate the roles of IP addresses in identifying hosts and routing packets.
22. IPSECKEY Record
IPSECKEY record deals with Internet Protocol Security (IPsec) and stores public keys for it. This helps secure IP communications by providing keying material.
23. LOC Record
LOC is the location record and specifies the geographical location of a domain name, including latitude, longitude, and altitude.
24. RRSIG Record
Also known as ‘resource record signature’, the RRSIG record contains the digital signature of a DNSSEC-signed record set. It ensures data integrity and authenticity.
Importance of DNS Records
DNS (Domain Name System) records are essential to the Internet’s infrastructure. They serve as the authoritative mappings between domain names and their corresponding resources.
- Domain Name Resolution: DNS records translate domain names into numerical IP addresses that computers use to identify each other on the network. With this translation process, internet users reach their desired destinations quickly and reliably.
- Efficient Internet Navigation: DNS records provide authoritative records of where users can find specific information by acting as roadmaps. They help in seamless interaction with websites across the Internet.
- Email Delivery and Security: Specific DNS records, such as MX (Mail Exchange) and SPF (Sender Policy Framework), are important for directing email traffic and preventing email spoofing. These records ensure reliable and secure email communication.
- Load Distribution and Performance Optimization: DNS records help in network traffic distribution across multiple servers. This distribution enhances website performance and reliability.
- Security Enhancements: Records like DNSSEC (DNS Security Extensions) add a layer of security by ensuring data integrity and authenticity. This added layer of security protects against certain types of cyber threats.
Conclusion
Did you know all these types of DNS records? With DNS records, you can access domain names in human-readable form. Hence, DNS records and the types of records are a significant part of the domain name system.
