At its most basic definition, the Domain Name System (DNS) is the phone book for the internet (remember those?). When you type in a domain name, it tells your computer the address of the computer you’re trying to access. It’s like having an Eircode for every website there is. This is so that we don’t need to know the IP address of everything we visit. We simply have to know the domain name, which is pointed at the IP address.
DNS records key facts:
- DNS records are stored on DNS servers.
- DNS records are updated dynamically, so they can be changed without having to restart your computer or device.
- DNS records are important for the proper functioning of the internet.
DNS records are the data structures that store information about DNS names and their associated IP addresses. There are many different types of DNS records, each with a specific function. Some make your website work. Some tell the world you have an email address. Others can be used for domain verification (because only the owner has access to the DNS records).
Here are a few examples of the most important DNS records that anyone with a domain name should know about:
‘A’ record (Address record): This is the most common type of DNS record and the most important. It tells the world where your website is hosted. It maps a domain name to an IPv4 address. For example, the A record for “google.com” would point to the IP address 172.217.14.238. Multiple websites can share the same IP address; in fact, that is the most common form of web hosting. Subdomains are another important form of A Record. Subdomains are essentially separate sections of a main domain. For example, if the main domain is “example.com”, a subdomain could be “blog.example.com”. A subdomain DNS record maps the subdomain to an IP address so that when someone types in the subdomain, they are directed to the correct location on the internet.
Wildcard A Record DNS Records: A wildcard DNS record is used to redirect all subdomains of a domain name to a single location. It is denoted by an asterisk (*) and can be used to redirect traffic from any subdomain that does not have a specific DNS record. For example, if you have a wildcard DNS record for “*.example.com,” that points to “www.example.com”, any subdomain that does not have a specific DNS record (such as “blog.example.com” or “shop.example.com”) will be redirected to “www.example.com”. This can be useful for managing large numbers of subdomains or for creating a catch-all website.
AAAA record (IPv6 address record): This is the IPv6 equivalent of an A record. It maps a domain name to an IPv6 address. It’s not a bad idea to future-proof your DNS records by making sure you set this up if you have IPv6-enabled hosting.
CNAME record (Canonical name record): This record is used to create an alias for a domain name. For example, the CNAME record for “www.google.com” could point to the domain name “google.com”. This would allow users to access the website at either “www.google.com” or “google.com”. What’s the difference between a CNAME record and a wildcard record? The main difference between the two is that a CNAME record creates an alias for a specific subdomain or domain name, while a wildcard DNS record redirects all subdomains that do not have a specific DNS record to a single location.
TXT record (Text record): This record can be used to store arbitrary text strings. It is often used to store information about a domain, such as its name servers or its contact information. But it has also become an important tool for domain verification as it can tell a service who really owns a domain name since only the owner has access to the DNS records.
MX record (Mail exchange record): This record is used to specify the mail servers for a domain. When an email is sent to a domain, the mail server will look up the MX record for that domain and deliver the email to the appropriate mail server. This is the most basic function needed to make email work. There are also several important email-related DNS records, such as DKIM, SPF, and DMARC, that we will cover in a future blog post.
NS record (Name server record): This record is used to specify the name servers for a domain. Name servers are responsible for storing and resolving DNS records. Usually, this will be the service where the domain was registered, but there are plenty of other services that let you hostname service DNS records (like Cloudflare).
These are just a few of the most commonly used DNS records. There are many other types of DNS records, each with its own specific purpose. If you are interested in learning more about DNS records, there are many resources available online. You can also consult with a DNS administrator or your domain registrar. If you need help with your Blacknight DNS records, see these helpdesk documents, or get in touch with Blacknight support.