What are DNS and name servers?
DNS, the Domain Name System, is the internet's phone book. When you type “digiserv.no” in your browser, DNS looks up which address the name points to and sends you there. Without DNS, you'd have to remember strings of numbers instead of names.
Name servers
Name servers are the servers that hold the DNS records for your domain. They answer questions like where the email server is, what address the website has, and who's allowed to send email from the domain. Each domain usually has two or more name servers, and they're registered with the domain registrar, which for .no is Norid.
The most common record types
| Record type | What it does | Example |
|---|---|---|
| A | Points the domain to an IPv4 address | The web server |
| AAAA | The same, for IPv6 | |
| MX | Says which server receives email | Exchange Online |
| CNAME | Alias that points to another name | www to digiserv.no |
| TXT | Free text, used for SPF, DKIM, DMARC and verification | v=spf1 include:… |
| NS | Says which name servers the domain uses | a.ns.digiserv.no |
What is TTL?
TTL, Time To Live, says how long other servers and browsers may cache a record, measured in seconds. A TTL of 3600 means the record is remembered for one hour before it's checked again. If you change a record with a TTL of 3600, it can take up to an hour before everyone sees the new value. Before a planned change, we usually lower the TTL to five minutes so the switch happens quickly.
When you switch providers
If you switch your website, email or hosting provider, the DNS records have to point to the new provider. There are two ways to do this:
- Change individual records. You keep the name servers and change only the records involved, for example the MX record when you switch email. Everything else works as before. This is what we recommend in most cases.
- Switch name servers. You point the whole domain to the new provider's name servers, and they control all the records. The downside is that all existing records have to be entered again with the new provider.
What can go wrong
- Email stops because the MX record is wrong. Always double-check MX before you make changes.
- The website is down because the A record points to the wrong place. Test in advance.
- It takes a long time because the TTL was high. Lower the TTL a day ahead.
- SPF and DKIM are forgotten when you switch email providers, and your email ends up in spam.
If your domain is with us, you change the records yourself in the control panel. See DNS. We're happy to help with switching providers and troubleshooting. Call 38 27 80 00.