DHCP server. How does it work?

To keep running a network demands dividing administrators’ attention and time among many tasks. All are necessary. Some are really exciting. And others… Well, no job is perfect. Others can be really boring, and besides, they can require a lot of time.

Fortunately, technology is focused not only on developing new and amazing stuff but also on making daily and boring tasks easier, sometimes automatic. And that is the case of DHCP. 

What is DHCP?

Dynamic Host Configuration Protocol (DHCP) is a management protocol very used on networks (TCP/IP) through its installation on servers. It is a tool for assigning IP addresses and more needed data automatically. Networks and connected devices to communicate need default gateways, subnet masks, and other configurations. 

DHCP allows network administrators to comply with these tasks without manually setting a static IP address for every device connected. Traditionally, after doing so, they need to monitor the use of every assigned IP to know when it’s free again, to give it to a different device. They also have to administrate them smartly, not to run out of the resource (IP addresses) for new clients. 

With a DHCP server, all can be configured to happen automatically. 

How does DHCP work?

To enjoy DHCP benefits, the server and client must have the protocol enabled. It is a server-client mechanism.

DHCP’s functionality operates through the combination of the following components. 

A server with DHCP installed. It holds the necessary IP addresses and information for devices to get connected. It is responsible for complying with the complete cycle: responding to IP requests, supplying available ones, checking the lease time, and renewing them. This role can also be played by a computer, router, or a different host.

Clients with DHCP. They are the users that require access to the network and, therefore, the resources to connect – all kinds of Internet of Things (IoT) devices, smartphones, computers, laptops. 

DHCP relay agent. A host in charge of getting clients’ requests to send them to a setup server properly. A TCP/IP plays this role in transporting requests and responses between clients and servers.

An IP addresses’ set. Systems need enough IP addresses to attend to all network’s DHCP clients.

The lease. It refers to the time lapse that IP address information is in use by DHCP clients. A DHCP server supplies a dynamic IP address to each client that requires it. They use it as long as the lease doesn’t expire. Once it does, a renewal will be needed. 

Subnets. With the growth of networks, it’s not rare they get split into different parts to administrate and maintain them easily. Every part is a subnet.

Why do I need a DHCP server?

Administration, supply, monitoring, and renewal of IP addresses will become a dynamic and automated process. You set up your preferences on the DHCP server, and after that, the process will run without the need for permanent supervision.

Automation minimizes errors. Every device (computer, smartphone, etc.) needs a unique IP address to connect to the network and to work well. One specific IP address can’t work at the same time for different devices. The connection will fail. Leases need to be checked and renewed. Endpoints must be changed, etc. Doing this manually can overwhelm even the most organized administrators. High demand can easily surpass them and drive to errors. DHCP is an efficient solution to avoid this.

You configure, modify and upgrade quite simply. Your settings will be saved and propagate for everything to run smoothly.


DHCP is the kind of network component not really visible, but its functionality is clearly proven on a more efficient performance. It is an excellent partner that will add real benefits to your network.

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