Dynadot

Dynadot Dynamic DNS (DDNS) Setup

This page documents how to configure Dynamic DNS for Dynadot and automatically update the A record when the public IP address changes.

Requirements

• Dynadot account
• Domain using Dynadot DNS
• DDNS password generated in Dynadot
• Ubuntu server with outbound HTTPS access

Dynadot configuration

1. Enable Dynadot DNS

1. Log in to Dynadot
2. Go to My Domains
3. Click the domain
4. Set DNS → Dynadot DNS

2. Enable Dynamic DNS

1. Domain settings → Dynamic DNS
2. Enable DDNS
3. Generate a DDNS password
4. Save it securely

3. Required values

Field	Example
Domain	example.com
Subdomain	@ or www
Record type	A (IPv4) or AAAA (IPv6)
DDNS password	(generated in Dynadot)

Dynadot update endpoint

Dynadot accepts HTTP GET updates:

https://www.dynadot.com/set_ddns

Parameters:

• domain
• subDomain
• type
• ip
• pwd
• ttl (optional)

Ubuntu auto-update script

Script: dynadot-ddns.sh

#!/bin/bash

DOMAIN="example.com"
SUBDOMAIN="@"
TYPE="A"
PASSWORD="YOUR_DDNS_PASSWORD"
TTL="300"

IP_FILE="/tmp/dynadot_last_ip.txt"

CURRENT_IP=$(curl -s https://checkip.amazonaws.com)

if [ -z "$CURRENT_IP" ]; then
    exit 1
fi

if [ -f "$IP_FILE" ]; then
    LAST_IP=$(cat "$IP_FILE")
else
    LAST_IP=""
fi

if [ "$CURRENT_IP" = "$LAST_IP" ]; then
    exit 0
fi

UPDATE_URL="https://www.dynadot.com/set_ddns?containRoot=true&domain=${DOMAIN}&subDomain=${SUBDOMAIN}&type=${TYPE}&ip=${CURRENT_IP}&pwd=${PASSWORD}&ttl=${TTL}"

curl -s "$UPDATE_URL" > /dev/null

echo "$CURRENT_IP" > "$IP_FILE"

Installation

1. Save script

sudo nano /usr/local/bin/dynadot-ddns.sh

Paste script and edit variables.

2. Make executable

sudo chmod +x /usr/local/bin/dynadot-ddns.sh

3. Test manually

/usr/local/bin/dynadot-ddns.sh

4. Add cron job (every 5 minutes)

crontab -e

Add:

*/5 * * * * /usr/local/bin/dynadot-ddns.sh

Security notes

• Store DDNS password securely
• Limit file permissions
• Do not commit the script to public repositories

References

• Dynadot Help – Dynamic DNS
• Dynadot API documentation