Setting up Simple Dynamic DNS

Dynamic DNS (DDNS) lets you keep a DNS record updated automatically when your IP address changes. This is especially useful if your ISP assigns you a dynamic IP, but you still want to reach your home network or server using a fixed domain name.

With DNSimple, you can use our API to build simple Dynamic DNS updates. For examples and ready-to-use options, check out our Tools page.

Before you begin

You need:

A DNSimple account with an active domain.
An API access token.
Basic familiarity with making HTTP requests (or a tool like curl).

DNSimple does not support the legacy dyndns API that many consumer routers reference when they mention DDNS. Instead, you must use our API or a compatible client.

Step 1: Identify the record you want to update

Decide which DNS record you want to keep updated with your dynamic IP address.

Typically, this will be an A record for a subdomain like home.example.com.
You can add an A record in your DNSimple dashboard before you start.

Step 2: Write a script or use a client

You can update the record programmatically by calling the DNSimple API. Here’s a simple curl example to update an A record:

curl -H "Authorization: Bearer \<API\_TOKEN\>" \
     -H "Accept: application/json" \
     -H "Content-Type: application/json" \
     -X PATCH \
     -d '{"content":"<YOUR_CURRENT_IP>"}' \
     https://api.dnsimple.com/v2/<ACCOUNT_ID>/zones/example.com/records/<RECORD_ID>

Replace <API_TOKEN>, <ACCOUNT_ID>, <RECORD_ID>, and <YOUR_CURRENT_IP> with your own values.
To get the current IP automatically, you can use a service like https://ifconfig.me in your script.

Example with shell substitution:

CURRENT_IP=$(curl -s https://ifconfig.me)
curl -H "Authorization: Bearer $API_TOKEN" \
     -H "Accept: application/json" \
     -H "Content-Type: application/json" \
     -X PATCH \
     -d "{\"content\":\"$CURRENT_IP\"}" \
     "https://api.dnsimple.com/v2/$ACCOUNT_ID/zones/example.com/records/$RECORD_ID"

Step 3: Automate the update

Run your script on a schedule to keep your DNS record synced with your current IP:

On Linux/macOS: use cron.
On Windows: use Task Scheduler.

For example, update every 5 minutes with cron:

*/5 ****/path/to/update-script.sh

Step 4: Verify the record

Check that your DNS record updates correctly:

dig home.example.com

The returned IP should match your current IP address.

Have more questions?

If you have additional questions or need any assistance with Dynamic DNS, just contact support, and we’ll be happy to help.