What are DNS records? What do A, CNAME, MX, TXT, SRV and CAA do?

In short: DNS is the phone book that turns a domain name into a server, a mail route or a verification value. An A record points to the site's server, MX to where mail goes and TXT to verification and signature values. The SITEKODO DNS screen manages A, AAAA, CNAME, MX, TXT, SRV and CAA records; it does not write a new record that conflicts with an existing one without asking.

What exactly is DNS?

Computers talk with addresses, people with names. DNS turns a name like example.com into a number the computer understands. Your domain's DNS zone is the list of these translations, and each line is called a record. When you change a record, resolvers around the world may not see the change at once; this is called propagation and takes minutes, sometimes hours.

What does each record type do?

| Type | What it does | Example use | |---|---|---| | A | Turns a name into an IPv4 address | Pointing to the site's server | | AAAA | Turns a name into an IPv6 address | The IPv6 counterpart of an A record | | CNAME | Redirects one name to another name | Linking www to the main name | | MX | Says where mail is delivered | Pointing to the mail server | | TXT | Carries free text | SPF, DKIM, DMARC and ownership verification | | SRV | Gives the server and port of a service | Some chat and call services | | CAA | Limits which authorities may issue certificates | Narrowing certificate authority |

The screen does not list NS, SOA and DNSSEC records, because showing a row that cannot be edited would tell the user they can touch it.

Which record do I enter to connect a domain to my site?

1. Enter an A record for the domain and write the address of the server where the site is hosted.
2. Add a CNAME for www pointing to the main domain, so both addresses open the same site.
3. Wait for the change to propagate. If the A record does not point to the server, the secure connection (SSL) certificate cannot be obtained, because certificate validation depends on the domain pointing to the right server.

The publish screen shows the order of these steps above the button: is the A record in place, not in place, or unknown? If the domain's DNS is not at SITEKODO we cannot read the record and the status says "unknown"; saying "done" would be approving something we did not look at.

Which records do I need for email?

To connect to a mail service you need an MX record and TXT records for signatures and sender verification. You can find the details in the SPF, DKIM and DMARC guide. A wrong MX sends your mail elsewhere, so note the existing record before changing it.

How does the SITEKODO DNS screen behave?

The screen has three rules:

1. It does not duplicate a record. If an identical record exists, the provider is never contacted and no second row appears. A duplicated MX splits mail; this rule prevents it.
2. Touching an existing record is a separate decision. If a record of the same type and name with different content exists, the screen stops and puts today's record next to what you asked for. It offers two options: replace the existing one or add it as a second record. For CNAME the second option is not shown, because a name cannot be both a CNAME and something else.
3. A trace remains. Which record was changed, when, by whom, and from what to what is written to a ledger. The ledger cannot be edited afterwards, because a trace that can change is not a trace.

Common mistakes

• Putting a CNAME on the root domain: A CNAME on the root cannot coexist with other records.
• Two SPF records: A domain should have a single SPF record.
• Pointing the A record to the wrong server: The site will not open and no certificate can be obtained.
• Adding the new record without removing the old one: The same name going to two places sends some visitors to the old one.
• Not waiting for propagation: Wait a little before saying "it does not work" right after a change.

How do I undo a change?

The ledger holds the before and after value of every change. After a bad change you can read the old value from the ledger and write it back from the same screen. Even so, taking a screenshot of the existing records before a big change is still a good habit.

Ready? Manage your DNS records on SITEKODO.