Computers find each other using numbers called IP addresses. People prefer names. The Domain Name System, or DNS, is the service that translates one into the other. It is often described as the address book of the internet.
What happens when you visit a website
- You type
yourname.orginto a browser. - Your device asks a DNS resolver, usually run by your internet provider, where that name lives.
- The resolver asks a chain of DNS servers, ending with the nameservers responsible for your domain.
- Those nameservers reply with the answer, such as an IP address.
- Your browser connects to that address and loads the website.
This usually takes a fraction of a second, and the answer is remembered for a while so the next visit is faster.
Nameservers
Every domain names the nameservers that hold its DNS records. Your registrar lets you set them. They might belong to the registrar, your hosting company, or a specialist DNS provider. Whoever runs your nameservers is where you edit your records.
The records you will meet most often
- A record: points a name to an IPv4 address, such as
192.0.2.10. - AAAA record: the same, for the newer IPv6 addresses.
- CNAME record: points one name to another name, such as
wwwtoyourname.orgor to a host’s address. - MX record: says which service receives email for your domain.
- TXT record: holds text used to prove you own the domain and to protect email from spoofing, including SPF, DKIM and DMARC.
Why changes take time
Each record has a TTL, or time to live, which tells resolvers how long to remember the answer. After you change a record, some visitors may see the old answer until their cached copy expires. With typical settings this ranges from a few minutes to a day or two.
Good habits
- Note down your existing records before changing anything.
- Change one thing at a time and check the result.
- Copy values exactly; a missing dot or character is the most common cause of trouble.
If you are a Courthology member, you can ask us to make DNS changes for you.