All About DNS & How To Use It
What Is DNS?
If you’re browsing the internet, you might not realize it, but every time you type in a website’s address, you’re using DNS.
DNS, or Domain Name System, is the system that translates human-readable domain names like “google.com” into machine-readable IP addresses. This is what allows your computer to connect to the website’s server and view the page.
DNS is essential because it simplifies the process of accessing websites and makes it much easier for people to remember and navigate to websites using simple names, referred to as “domain names”.
Think of DNS as like a phone book or a directory. Rather than having to remember a lengthy strings of numbers for every single location, you can just remember a name. Your computer can then look up the address for you.
DNS is also critical to the overall function of the internet and is necessary for things like email, file sharing, and other internet-based services.
There are many different types of DNS records. Here are some of the most common:
- A Record: Assigns an IPv4 address to a domain name or subdomain.
- AAAA Record: Assigns an IPv6 address to a domain name or subdomain.
- CNAME Record: Creates an alias that tells a subdomain to point to another A record.
- TXT Record: Associates text with your domain. Usually used for settings, identity verification, or other specific purposes.
- MX Record: Specifies the (sub)domain for a your mail server(s).
- NS Record: Specified the official nameservers for your domain.
- PTR Record: Maps an IPv4 address to a domain (basically the reverse of an A record).
- SOA Record: Specifies the authority information for your domain.
- SRV Record: Specifies the information for other services.
For a much more complete list, please see this list of 20+ DNS records.
What is An SOA Record?
An SOA record defines the start of the authoritative record for your domain.
It serves as a reference point for the DNS server, indicating the primary authoritative name server for the domain. The SOA record contains various details such as the domain administrator’s email address, the zone’s serial number, and various timing parameters for zone updates and data propagation.
In essence, the SOA record helps manage and synchronize the DNS records across multiple DNS servers, ensuring accurate and consistent domain name resolution across the internet.
What Is A PTR (Reverse DNS) Record?
A PTR record, or Pointer record, is a type of DNS record that maps an IP address back to its corresponding domain name. You can think of this as the inverse of an A record.
This reverse mapping process plays an important role in email server authentication and network diagnostics. It’s used by many email servers to ensure that your email server’s domain isn’t being spoofed. This ensures that the domain sending the email corresponds to the email server that sent the message.
By having a PTR record, you can help improve email deliverability. Some email servers will require a PTR record from your server in order to accept your email at all, while it can help improve the reputation of your server to other email providers.
What Is a Wildcard DNS Record?
A DNS wildcard record is a special DNS entry that acts as a catch-all for requests to non-existent subdomains, simplifying domain management by reducing the need for individual records.
The DNS You Need…
If you’re setting up the DNS for a WordPress website, you’ll likely need to have:
- an A record pointing to your main hosting server,
- a CNAME record for the “www” version of your site,
- MX records for your mail (if you’re using mail on your domain),
- NS record(s) specifying the nameservers for your domain,
- an SOA record, and
- possibly others depending on your requirements
If you’re setting up your own email server, you’ll probably need the following DNS records:
- MX records specifying your email server,
- SPF record(s) for specifying which servers can send email from your domain,
- DKIM record(s) for cryptographically signing your emails,
- DMARC record(s) for receiving notifications about emails that fail these checks, and
- PTR record(s) for verifying the IP of your email servers.
DNS Propagation & Why It Takes a While
DNS propagation refers to the time it takes for changes to DNS records to take effect.
When you update your DNS records, such as changing your website’s IP address or switching to a new web hosting provider, it can take some time for these changes to propagate across all DNS servers globally. It can take a while for the DNS caches to expire and for servers to look up the new records.
The length of time it takes for DNS propagation to complete can vary depending on several factors, including the TTL (time-to-live) setting of your DNS records and the number of DNS servers that need to update their caches. There isn’t a guaranteed way to speed it up, but there are ways to potentially improve the speed of your DNS propagation.
Separating DNS Records
What Is Anycast DNS?
Anycast DNS is a networking technique that enables DNS queries to be routed to the geographically nearest server among multiple servers sharing the same IP address.
This method is widely used for improving the performance, security, and resilience of DNS infrastructure. By directing DNS queries to the closest available server, Anycast DNS minimizes latency, reduces response times, and ensures faster DNS resolution for end users.
Additionally, the distributed nature of Anycast DNS servers offers enhanced security by making it more difficult for attackers to target specific servers, while providing built-in redundancy to mitigate server outages and failures. Overall, Anycast DNS is a powerful and efficient solution for managing DNS traffic, improving speed and reliability.
What Is Split-Horizon DNS?
Split-Horizon DNS is a configuration technique where internal and external DNS records are segregated, allowing you to secure and optimize network performance. By serving different sets of DNS records to internal and external clients, you can protect sensitive information and better manage network traffic. You can also use split-horizon DNS to separate traffic by geographic region if needed.
What is GeoDNS?
GeoDNS is a method of using the location of your visitors to serve them different content based on their location. It allows you to manage your network traffic without a lot of the configuration issues of Anycast DNS, and to get your visitors faster loading times.
What is DNS Over QUIC?
DoQ provides encrypted, faster, and more resilient domain name resolution by utilizing QUIC’s built-in encryption with:
- TLS 1.3,
- reduced latency through 0-RTT connection establishment, and
- connection migration for seamless network transitions.
Additionally, DoQ helps mitigate common DNS attacks, such as DDoS, amplification, and cache poisoning attacks. It also maintains compatibility with existing DNS infrastructure and coexists with other DNS encryption methods like DoT and DoH.
What Is DNSSEC?
DNSSEC, or Domain Name System Security Extensions, is a crucial security protocol designed to protect the integrity and authenticity of DNS data. By employing public and private cryptographic keys along with digital signatures, DNSSEC offers a robust method for validating DNS information.
Implementing DNSSEC helps safeguard against various DNS attacks, such as cache poisoning, ensuring a secure and reliable online experience for website visitors.
DNS Over HTTPS (DoH) is an protocol that enhances your online privacy and security by encrypting your DNS queries. When you’re browsing the web, DoH sends your DNS requests within encrypted HTTPS traffic instead of the traditional plaintext format. This makes it much more difficult for eavesdroppers or hackers to intercept or tamper with your DNS traffic.
- dig: Dig is a command-line tool used for querying DNS servers to retrieve information about domain names, IP addresses, and various DNS records.
- nslookup: nslookup is a command-line tool used to query and troubleshoot DNS configurations by resolving domain names to IP addresses and vice versa.
Advanced DNS Topics
Internationalized Domain Names (IDNs) are domain names that incorporate characters from non-Latin scripts, enabling a more inclusive and accessible internet for users who speak different languages. These domain names support a wide range of scripts, such as Arabic, Chinese, Cyrillic, and many more, allowing websites to use domain names in their native languages.
The primary benefits of IDNs include fostering a more inclusive online environment, connecting with diverse audiences, and enhancing user experiences by presenting domain names in familiar scripts. By embracing IDNs, businesses and organizations can better serve their target audiences, strengthen their online presence, and contribute to a more diverse and culturally rich digital landscape.
What Is EDNS0?
EDNS0 is the first version of Extension Mechanisms for DNS, designed to extend the capabilities of the DNS protocol. It’s designed to do this without altering its base structure of DNS packets. It enables larger UDP message sizes, DNSSEC support, and additional options for improved functionality and security.