DHCP

DHCP (Dynamic Host Configuration Protocol) is a service that automatically assigns an IP address, subnet mask, gateway, and DNS servers to devices when they connect to a network. Without it, an administrator would have to manually configure every computer, phone, and printer.

A DHCP server manages a so-called address scope and keeps a record of which address is assigned to which device and for how long it is valid (the lease). When the lease expires, the device either renews the address or receives a new one.

In a business environment, DHCP typically runs on a firewall, router, or domain controller; reservations are used for servers and printers to ensure their addresses remain constant.

Practical examples

A company with 60 employees has separate scopes for the office network, guest Wi-Fi, and IP telephony. Printers and servers have reservations so that their addresses never change.

Business relevance

A misconfigured DHCP is a common cause of downtime: devices fail to receive an address, duplicate addresses cause interruptions, and an insufficient scope means some users remain disconnected.

Common mistakes

The most common mistakes are an undersized address scope, two DHCP servers on the same network (e.g., an ISP router that has not been disabled), and the lack of reservations for critical devices.

How VitalIT helps

At VitalIT, we design, deploy, and maintain business networks — segmentation, Wi-Fi, VPN, and firewalls. Learn more on the IT infrastructure page.