How do DHCP and DNS differ?



"DHCP is the fully automatic integration of a new computer into an existing network without any further configuration. Normally, only the automatic acquisition of the IP address must be set on the client. Obtain DNS server and possibly also WINS server from a DHCP server automatically. Without DHCP, relatively complex settings are required - depending on the network to which the computer is to be connected. " (Source Wikipedia)

DHCP in the WiFi and MedVer network

The requirement for the use of DHCP in the two networks of the faculty or the clinic is a correct entry of the computer in the device database and, in particular, the correct MAC address. On the basis of this, the DHCP server decides whether a device is assigned an IP address and, if so, which one. A distinction must be made between the "static" and "dynamic" interface services. With both services, the device can be configured to DHCP in the network settings.

"static" versus "dynamic" DHCP

In the case of a device that has a static service in the device database (e.g. "MedVer static"), an entry is created in the DHCP server that has a fixed assignment to a specific IP address. This means that this PC always gets this IP address. At the same time, the name of this device is entered in the DNS with the associated IP address. This means that it is not possible for a static device to simply move to another area of ​​the campus.

The situation is different with dynamic services. Here, only the MAC address is entered in the DHCP server with the note that a device with this MAC address is authorized to obtain an IP address via DHCP. The DHCP server decides which IP address is assigned to a device depending on the subnet in which the device is located. Such a device can work at several locations in the network without having to change the IP address on the device.

The DHCP server automatically enters the correct DNS name (device name + subdomain of the facility). The device can thus be reached immediately, regardless of which IP address it has been assigned.

Which DHCP for whom

For servers and other devices that rely on a fixed name or an always constant IP address, the "static" service should be selected.

The "dynamic" service should be selected for normal workstation PCs, laptops, printers and devices that are operated at several locations. In addition to the advantage of being able to operate the device at several locations without having to manually change the IP address, even with "normal" PCs there is no need to apply for a new IP address when moving.