DHCP short for: Dynamic Host Configuration Protocol.
This protocol serves for the dynamic configuration of IP addresses and related information.
DHCP supports a centralized administration of limited IP addresses. Once a host is up and running, it will register itself at the DHCP server. The server assigns a free IP address to the device, which stores it locally. This IP address is valid for a certain period of time, called "lease time". After expiration a renewal or extension is necessary.
Each device in a LAN needs to have a unique IP address, comprised bei four pairs of numbers. To simplify the handling of IP addresses for humans, all device have an unique name, called host name. The allocation of IP address to host name and vice versa is done by the Domain Name System (DNS).
The Domain Name System is set up hierarchically. On top are the Top Level Domains (TLDs),e.g. .tw oder .com. One step below you will find Second Level Domains (SLDs, also called Domains), e.g. dlink.tw. Each step in the hierachy is separated by a "."(dot). Every domain can be registered only once, as she has to stay unique.
If the ${_global.productname} works as DHCP server in your LAN, local IP addresse can be handed on in two way:
Sometimes it makes sense to assign static IP addresses for certain device, e.g. for security reasons.
A static IP address is bound to the MAC address of the device. This IP address is not longer handled by the DHCP server.