Understanding DNS
Learn how DNS works, what each record type does, and how to edit them safely.
Richard Sutherland
Beginner
DNS lets people use names while computers use numbers. This opening tutorial explains the problems DNS solves, how a DNS lookup works, and why DNS is so important to everythnig you do online.
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- 1
- 8 min
Richard Sutherland
Beginner
Domain management often involves several companies, which can get confusing. This tutorial sorts out who runs the registry, who sells the domain, who hosts the DNS, and where you make to changes to it all.
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- 8 min
Richard Sutherland
Beginner
DNS records are the instructions attached to your domain. You'll meet the four record types that come up most often and learn how to understand what they are saying.
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- 9 min
Richard Sutherland
Intermediate
Changing DNS settings can feel risky, but only when you don't have a safe routine to follow. This tutorial walks you through the safe order of operations, from finding the right control panel to checking that the new record is really live.
- 41
- 10 min
Richard Sutherland
Intermediate
Pointing a domain at a website sounds simple until the root domain and subdomains start behaving differently. This tutorial clears up when to use an A record, when a CNAME makes life easier, and how the pieces fit together.
- 56
- 9 min
Richard Sutherland
Intermediate
Email DNS has two jobs. It needs to get incoming mail to the right place, and it needs to prove your outgoing mail is legitimate. This tutorial covers both through the use of MX, SPF, DKIM, and DMARC.
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- 1
- 11 min
Richard Sutherland
Advanced
SRV records handle the services that need more than a hostname alone. They tell an app which server to use, which port to call, and how to choose when more than one endpoint is available.
- 56
- 9 min
Richard Sutherland
Advanced
Reverse DNS turns the usual lookup around and asks what name an IP address points back to. That matters most on servers, especially mail servers, where reputation depends on that answer making sense.
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- 9 min
Richard Sutherland
Intermediate
Most "DNS propagation" problems are really cache problems. Here, we show you how to tell whether the change is already correct at the source, which layers may still remember the old answer, and how to cut down propagation wait time.
- 50
- 11 min
Richard Sutherland
Advanced
DNS only works if the answers can be trusted. The final tutorial looks at what can go wrong, from spoofed responses to account takeover, and the protections you can put in place that do the most to reduce that risk.
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- 12 min