The Dynamic Host Configuration Protocol (DHCP) allowed enterprises and Internet service providers (ISPs) to assign addresses to computers automatically as they powered up.In addition, this helped conserve the address space available, since not all devices might be actively used at all times and addresses could be assigned as needed.
In the initial stages of the Internet (ARPANET) addressing of hosts on the network was achieved by static translation tables that mapped hostnames to IP addresses.
The tables were maintained manually in form of the host file.
The first is "dynamic DNS updating" which refers to systems that are used to update traditional DNS records without manual editing.
These mechanisms are explained in RFC 2136, and use the TSIG mechanism to provide security.
The first is "standards-based DNS updates", which uses an extension of the DNS protocol to ask for an update; this is often used for company laptops to register their address.
The second is usually a web-based protocol, normally a single HTTP fetch with username and password which then updates some DNS records (by some unspecified method); this is commonly used for a domestic computer to register itself by a publicly-known name in order to be found by a wider group, for example as a games server or webcam.
The second kind of dynamic DNS permits lightweight and immediate updates often using an update client, which do not use the RFC2136 standard for updating DNS records.
These clients provide a persistent addressing method for devices that change their location, configuration or IP address frequently.
Dynamic DNS (DDNS or Dyn DNS) is a method of automatically updating a name server in the Domain Name System (DNS), often in real time, with the active DDNS configuration of its configured hostnames, addresses or other information.
The term is used to describe two different concepts.
This feature required that DNS servers be kept current automatically as well.