DNS

What is dynamic DNS
and how does it work?

In the early days of the internet, IP addresses seldom changed. But as the internet has evolved, so have the needs of the sites and services that rely on it, making static (or unchanging) IP addresses more difficult to obtain. To solve this problem, the Dynamic Host Configuration Protocol (DHCP) was developed. Thanks to DHCP, internet service providers (ISPs) can assign IPs dynamically from a pool of available addresses.

What is dynamic DNS?

Dynamic DNS (DDNS) automatically checks for updated IPs for websites, servers or apps. While DDNS is most often associated with home use, businesses providing services without static IPs also use DDNS. This service can be used for a number of purposes, including email, ftp, web and game servers, as well as security cameras and virtual private networks (VPNs).

How does DDNS work?

The implementation of many DDNS services uses provider-based software or a DHCP server that runs on a system. When the DDNS client detects changes, it passes any necessary arguments for http or https URL requests along to resolvers, and the software or DHCP server alerts all systems of changes to a domain or application’s IP address. This allows IP updates to be propagated instantaneously with no service interruptions. 

What’s the difference between DNS and DDNS?

The main difference between DNS and DDNS is that regular DNS points to static IPs and requires manual updates, while DDNS uses dynamic IPs, continually checking for changes and updating the IPs automatically.

What are the benefits of DDNS?

Some applications and APIs need to be accessible at all times but do not or cannot use static IP addresses. Not having a static IP means that domains pointing DNS records to a specific address could be inaccessible for the 24-48 hours between the change’s initiation and the time it’s propagated across all servers worldwide.

An inaccessible domain would pose a major problem for both businesses and end users, but DDNS solves the problem by creating a dynamic A record. Instead of requiring an IP address to be changed manually each time it’s been changed by an ISP, a DDNS service makes the change automatically, preventing any lag or downtime.

With DDNS, users can use a domain name to access IP addresses, just as they can with regular DNS. And since static IPs are much harder to obtain, using DDNS is cost-effective, especially for businesses that may require many IPs.