Dynamic DNS (DDNS) is a service that can automatically update DNS records when an IP address changes. Domain names convert network IP addresses to human-readable names for recognition and ease of use. The information mapping the name to the IP address is recorded tabularly on the DNS server. However, network administrators allocate IP addresses dynamically and change them frequently. A DDNS service updates the DNS server records every time IP addresses change. With DDNS, domain name management becomes easier and more efficient.
Why is dynamic DNS important?
In the past, IP addresses were static and rarely changed. However, there was a shortage of IP addresses due to the expansion of the internet and the massive increase in the number of servers, smart sensors, and end-user devices.
A new system called IPv6 was introduced to increase the number of IP addresses. However, allocating static IP addresses was no longer cost-effective. Instead, network administrators use Dynamic Host Configuration Protocol (DHCP) to assign IP addresses dynamically.
Why IP addresses change
Network administrators typically maintain a shared pool of IP addresses. They lease or assign IP addresses to users for a predetermined maximum amount of time or until they terminate their connection.
Whenever a machine joins a network, it gets a new dynamic IP address. When a machine logs off the network, DHCP reassigns IP addresses to all remaining devices. Hence, dynamic IP addresses can change frequently and at irregular intervals.
How dynamic DNS helps
Developers use domain names to identify application endpoints like APIs or specific server instances in their code. If DNS records are not up-to-date, bugs occur when end users try to access endpoints.
Dynamic DNS ensures that users can continue to access the device or service using the domain name. They don’t need to track and update the IP address manually.
What are the use cases for dynamic DNS?
Dynamic DNS offers several use cases for organizations. It provides flexibility, convenience, and improved accessibility.
Remote access
With Dynamic DNS, you can remotely access internal network resources, such as file servers, web servers, or remote desktop services. Employees can access these resources outside their organization’s network using a domain name associated with the changing IP address. This is particularly useful for organizations with remote workers, branch offices, or employees on the go.
Hosting services
Obtaining a static IP address for hosting is expensive, with pricing geared towards large enterprises. Early-stage startups and small businesses use dynamic DNS to host services or applications on internal infrastructure. They can host websites, FTP servers, game servers, or any other service that requires a consistent and accessible domain name.
Remote monitoring
Organizations that deploy surveillance cameras or remote monitoring systems utilize dynamic DNS to access and manage these systems remotely. First, you would associate a domain name with the changing IP address of the monitoring devices. Then, security personnel or administrators could view live feeds, monitor security events, and manage the system from anywhere with an internet connection.
Managing cloud instances
Organizations can have several cloud instances running different services that communicate with each other. Dynamic DNS is useful when you have instances that are not behind a load balancer. With it, you can address an instance by a hostname and domain suffix of your choosing.
How does dynamic DNS work?
Organizations typically subscribe to a dynamic DNS (DDNS) service provided by a DDNS provider. The provider also maintains the DNS servers that handle the DNS records for the associated domain name. Here are the general steps:
- You register a domain name with the dynamic DNS service provider and configure the DNS settings
- You provide the provider with the initial IP address for the domain name
- You install a dynamic DNS client on the device or server instance with the changing IP address
The DDNS client continuously monitors the IP address and detects any changes. It sends a DNS record update notification to the dynamic DNS provider, informing it of the new IP address. The dynamic DNS provider modifies the records to point to the new IP address.
The dynamic DNS client continues monitoring the IP address for further changes. Whenever a new change occurs, the process repeats.
What is the difference between DNS and Dynamic DNS?
A DNS service is a globally distributed service that translates human-readable names into numeric IP addresses. DNS servers translate requests for names into IP addresses. They control which server an end user will reach when they type a domain name into their web browser.
DNS vs. DDNS
Dynamic DNS (DDNS) is an extension of DNS that automatically updates IP addresses associated with domain names in real time. It expands the capabilities of DNS. With DDNS, organizations and individuals can maintain connectivity and accessibility even in dynamic IP address environments.
DNS is universally supported by all DNS servers and used globally to resolve domain names to IP addresses.
DDNS, on the other hand, requires the support of specific DDNS providers. Organizations must subscribe to DDNS services and configure their devices or routers to work with the chosen DDNS provider.
