What is DHCP

DHCP stands for Dynamic Host Configuration Protocol, a network management protocol used to dynamically assign Internet Protocol addresses to any device or node on the network so that they can communicate using IP.

#The operating environment of this article: Windows 7 system, Dell G3 computer.

DHCP (Dynamic Host Configuration Protocol) is a network management protocol used to dynamically assign Internet Protocol (IP) addresses to any device or node on a network so that they can communicate using IP.

DHCP automates and centrally manages these configurations, rather than requiring network administrators to manually assign IP addresses to all network devices. DHCP can be implemented on small local networks as well as large enterprise networks.

How does DHCP work?

DHCP operates in client/server mode, where the server sets up a pool of available IP addresses for the network.

The DHCP server is used to issue unique IP addresses and automatically configure other network information. In most homes and small businesses, the router acts as a DHCP server. In large networks, a single computer may act as a DHCP server.

In a nutshell, the process is as follows: the device (client) requests an IP address from the router (host), after which the host assigns an available IP address to allow the client to communicate on the network.

Once the device is turned on and connected to a network that has a DHCP server, it will send a request called a DHCPDISCOVER request to the server.

After the DISCOVER packet reaches the DHCP server, the server will try to reserve an IP address that the device can use, and then provide the address with the DHCPOFFER packet to the client.

Once an offer is made for the selected IP address, the device responds to the DHCP server with a DHCPREQUEST packet to accept it, after which the server sends an ACK which confirms that the device has that specific IP address and defines when the device is acquiring the new The time before the address was available for use.

If the server determines that the device cannot own an IP address, it will send a NACK.

Of course, all of this happens very quickly and we don't need to know any of the technical details we just read in order to obtain an IP address from a DHCP server.

The process of obtaining an IP address from the DHCP server is as follows:

1. The computer (client) configured to use DHCP The network sends a DHCP DISCOVER request.

2. The DHCP server receives the DHCP DISCOVER request, finds the available IP address pool and selects the IP address to be allocated. If the DHCP server was previously assigned an IP address, the DHCP server attempts to find the same IP address for the client. The DHCP server sends a DHCP OFFER response to the client.

3. The client receives the DHCP Offer response and replies to the DHCP server by sending a DHCP REQUEST packet to receive the offer.

4. The DHCP server sends an ACK (acknowledgement) packet to confirm the IP address allocation. If the IP address is no longer available, a NACK (No Answer) packet is sent and the process is repeated until the client receives a valid IP address from the server.

What are the benefits of using DHCP?

DHCP allows network administrators to centrally manage and automatically assign IP addresses without having to worry about assigning duplicate IP addresses to multiple computers and re-entering network gateways, subnet masks and other Network related information to each computer, thus making network management easier to manage.

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