A record or CNAME record: which one do you need?

Look at what the service gave you. If it gave you an IP address, a string of numbers like 192.0.2.10, add an A record. If it gave you a name, like shop.example-service.com, add a CNAME record. That is the whole rule, and it covers most cases.

An A record points a name at a number. A CNAME record points a name at another name, and lets that other name decide where the number is. Many services ask for both: an A record on the domain itself and a CNAME on www. For what every record type means, see Your domain's DNS settings explained.

Read what the service tells you

The instructions you were given come in two shapes, and sometimes both together.

An IP address. Add an A record. If the address has colons in it, like 2001:db8::10, it is IPv6, and the record type is AAAA instead of A. Everything else works the same way.

A name (a hostname). Add a CNAME record, and put the name in the Data field exactly as the service wrote it. The service can then move its servers around without asking you to change anything.

Both together. Typical wording: "A record for @, CNAME for www." Do both, exactly as written. In Sedes, @ means the domain itself, yourdomain.no, and www means www.yourdomain.no. If the service gives you both an address and a name for the same place, follow its instructions to the letter. It knows what its own servers expect.

Why the domain itself usually gets an A record

A CNAME makes a name an alias of another name. The DNS rule is that when a name has a CNAME, nothing else should be listed at that name. The domain itself is the one name that always has other records: the nameserver records, and usually mail (MX) and TXT records for email. So a CNAME there collides with them, and the usual result is that the website and the email both stop working.

That is why services ask for an A record on the domain itself and a CNAME on www: www usually has no other records, so a CNAME fits there.

Sedes does not stop you from adding a CNAME at @. The editor shows a warning instead: a CNAME at @ collides with the other records there, such as NS and MX, and can stop both the website and the email, so use an A record instead or put the CNAME on www. Read that warning as a real one. If you see it, change the record.

When the service only gives a name, but wants the bare domain

Sometimes the service gives you only a hostname and still wants your domain without www to work. A CNAME is the wrong tool there, for the reason above. Sedes has a record type for this, called ANAME. Sedes looks the name up and answers with the address it points to, so a hostname-only service can sit on the domain itself. Some DNS hosts call the same thing ALIAS.

Use ANAME only when the service asks for it.

Add the record in Sedes

Before you start, have the service's instructions open, and check that the domain uses Sedes's nameservers (the Nameservers tab shows which). Records added at Sedes only count while it does.

1. Log in at app.sedes.no. You land on Domains.
2. Click the domain and open the DNS tab. Choose Simple or Advanced. Simple shows A, AAAA, ANAME and CNAME records, which is all this guide needs. Advanced shows every type.
3. Click New record. A new row appears.
4. Fill in the row. The columns are Host, TTL, Type, Prio and Data. Prio only applies to MX and SRV records, so leave it empty here.
5. Click Save 1 change. The button counts your changes (Save 2 changes if you have made two). Discard throws away the changes you have not saved. Save opens Review changes, a list of what is added, removed or modified. Check it and click Apply 1 change at the bottom. Nothing changes until you do.

What to put in the row:

Use the values your service gave you, not these. They are examples. New records get a TTL of 3600 seconds unless you change it, which is fine.

If the service wants both, add both rows before you save, and apply once.

For the real values from one service, see Connect your domain to Shopify. It has Shopify's own addresses and names, so they are not repeated here.

Replacing an old record

If the domain already pointed somewhere, there is an old A record on @. Do not leave it there. When two A records sit on the same host, the nameservers answer with both, and visitors land on either one, so some of them keep reaching the old server. Delete the old A record when you add the new one: open its row, click Delete record, then save and apply. The editor also warns you when there is more than one A record at @.

Leave the MX and TXT records alone. They belong to your email, not your website. If you are setting up mail, How do I get email on my domain? covers those, including the DKIM records some providers ask for as CNAMEs.

How long until it works

A new record usually works within minutes. A changed record can take up to its old TTL, which at Sedes is an hour unless you set another. The DNS settings guide explains why the answer is "it depends": Your domain's DNS settings explained.

When it does not work

The site is still the old one. Wait out the time above first. If an old A record is still on the host, delete it.

Website and email both stopped after your change. You probably have a CNAME at @. Look for the warning in the editor. Replace it with an A record, or move the CNAME to www. Then check that your MX and TXT records are still there.

The service says the record is wrong, but it looks right. Compare Host and Data character by character with the service's page. A missing letter or a stray space in Data is the usual cause. Check that the domain really uses Sedes's nameservers, as above.

You are not sure which type the service wants. Write to hei@sedes.no with the service's instructions or a screenshot.

If none of these fits, write to hei@sedes.no with the domain name and what you see.

How this actually works

DNS is a lookup table. When someone types your address, their computer asks the nameservers for the number it should connect to. An A record is a table row that holds the number directly: this name, this IP address.

A CNAME is a row that holds another name instead. The computer asks again, for that name, and gets the number from there. This is what lets a service such as a shop platform change its servers without telling you. You point at its name, it keeps the name up to date.

The catch is the rule from earlier: a name with a CNAME is, in effect, only an alias, so it cannot also carry its own nameserver, mail and TXT records. The domain itself needs those, which is why it takes an A record, or ANAME, which is Sedes doing the second lookup for you instead of leaving it to the visitor's computer.

The DNS rule is that a name should have either a CNAME or other records. At @ the editor warns you, as described earlier. If you are unsure, write to hei@sedes.no with your domain name and what you see.

Sources

• RFC 1034, section 3.6.2 (CNAME and other data at the same name)
• RFC 2181, section 10.1 (CNAME resource records)

Read 11 November 2026.