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What Is Dynamic DNS?

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Dynamic DNS (DDNS or DynDNS) automatically updates your domain’s DNS records whenever the underlying IP address associated with your network or device changes. This technology is crucial for maintaining continuous connectivity to services hosted on networks with dynamically assigned IP addresses, found in many homes or small business internet connections. DNSimple supports Dynamic DNS through its API, but not through the DynDNS protocol that many routers use.

Traditionally, DNS records map a domain name to a static, unchanging IP address. However, many Internet Service Providers (ISPs) assign dynamic IP addresses to their residential and small business customers. These IP addresses can change frequently (e.g., daily, weekly, or after a router restart), which would normally break any services linked to a domain name. Dynamic DNS solves this problem by automating the update process, ensuring your domain always points to the correct, current IP address.

How Dynamic DNS works

Dynamic DNS involves coordination between your network, a specialized client, and a DDNS service provider like DNSimple:

  1. Dynamic IP assignment: Your internet service provider assigns a dynamic IP address to your router or network device. This IP address is not permanent and can change over time.
  2. IP change detection: A DDNS client (often built into your router or a small software application running on a computer within your network) constantly monitors your network’s public IP address.
  3. Notification to DDNS service: When the DDNS client detects that your public IP address has changed, it automatically sends an authenticated update request to your DDNS service provider (for example, DNSimple).
  4. DNS record update: The DDNS service provider receives this notification and updates the relevant DNS record (typically an A record for IPv4 or AAAA record for IPv6) for your domain or subdomain to reflect the new IP address.
  5. Resolution: Once cached copies of the old record expire, your domain name resolves to the new IP address. A short TTL on the record keeps that delay small.

Dynamic DNS with DNSimple

DNSimple supports Dynamic DNS through the DNSimple API. You can run a small script on a machine in your network, or configure a device that supports custom update URLs, to update a record in DNSimple whenever your IP address changes.

The tools page on our developer site lists Dynamic IP updaters you can start from, including an official one in Bash and community-developed ones in other languages.

Note

DNSimple does not support the DynDNS update protocol. Most routers with a built-in DDNS setting use that protocol, so they cannot update DNSimple directly.

Why use Dynamic DNS?

Dynamic DNS provides significant benefits for users ranging from individuals to enterprises:

  • Continuous reachability: Ensures your domain name always points to the correct IP address. This makes your services consistently accessible, even if your ISP frequently changes your IP.
  • No manual updates: Eliminates the need to manually log in to your DNS provider and update IP addresses every time they change, saving time and preventing downtime.
  • Cost-effective hosting: Enables you to host websites, personal cloud storage, security cameras, or other services from a home or office network without incurring the higher costs associated with static IP addresses from ISPs.
  • Remote access: Easily access devices or resources on your home or small business network remotely by using your domain name, rather than having to discover a constantly changing IP.

Have more questions?

If you have additional questions or need any assistance with Dynamic DNS, just contact support, and we will be happy to help. You can also read more about DNS hosting at DNSimple.