What Is DHCP (Dynamic Host Configuration Protocol)?

Wondering about DHCP? Here’s all about What is DHCP (Dynamic Host Configuration Protocol).

In trendy hyper-connected IT environments, admins should guarantee all the devices are designed. And connected during a network. Manual distribution IP addresses to each device are vulnerable to errors. This can be wherever Dynamic Host Configuration Protocol. Or DHCP configuration comes into play.

DHCP could be a network management protocol. Wherever a server assigns information processing addresses. And connected data to all or any of the devices on the network for effective communication. Not informatics addresses. Even so, DHCP may also configure a default gateway. Subnet mask, Name Server (DNS), and alternative relevant networking parameters.

What is DHCP (Dynamic Host Configuration Protocol)?

DHCP (Dynamic Host Configuration Protocol) is an application layer protocol. That is employed to provide:

  • DNS Address (Option six – e.g.,
  • Subnet Mask (Option one – e.g.,
  • DHCP relies on a client-server model and supported discovery, offer, request, and ACK.
  • Vendor category symbol (Option forty three – e.g., ‘unifi’ = ##where unifi = controller)
  • Router Address (Option three – e.g.,

The DHCP port diversification for the server is 67 and for the consumer is 68. The DHCP is a consumer server protocol that uses UDP services. The  IP address is assigned from a pool of addresses. In the DHCP, the consumer and thus the server exchange 4 DHCP messages. So on create an affiliation, known as the DORA method, even so, there are 8 DHCP messages within the method.

Read Also: DHCP Lookup Failed

DHCP offer message

The server can answer the host during this message specifying the unleased IP address. An alternative TCP configuration transmission control protocol. This message is broadcasted by the server. The size of the message is 342 bytes. If there is over one DHCP server available within the network. Then consumer host can settle for the primary DHCP offer message. It receives a server ID is per the packet so on the spot the server.

Now, for the source message, the supply information processing address is (Server’s information processing address within the example). Destination scientific discipline address is (Broadcast scientific discipline address), source mac address is 00AA00123456. Destination mac address is FFFFFFFFFFFF. Here, the supply message is broadcast by the DHCP server. This destination information processing address is the broadcast information processing address. And destination mac address is FFFFFFFFFFFF. And thus the supply IP address is a server scientific discipline address. And mac address is server mac address.

Also, the server has provided the offered scientific discipline address And lease time of seventy-two hours(after now the entry of host is erased from the server). The consumer identifier is laptop mac address (08002B2EAF2A) for all the messages.

DHCP inform

If a consumer address has obtained information processing address. Then the consumer uses a DHCP inform to get alternative native configuration parameters. Like domain name. Back to the DHCP inform message, the DHCP server generates a DHCP ack message. With native configuration appropriate for the consumer. While not allocating a brand new information processing address. This DHCP ack message is unicast to the consumer.

DHCP negative acknowledgement message

Whenever a DHCP server receives a missive of invitation. For information processing address that’s invalid per the scopes. That’s designed with, it sends DHCP NAK message to the consumer. Eg-when the server has no information processing address unused or the pool is empty. Then this message is distributed by the server to the consumer.

DHCP acknowledgement message 

In response to the request message received, the server can build an entry with a fixed consumer ID. And bind the information processing address offered with lease time. Now, the consumer can have the information processing address provided by the server.

Currently, the server can build an entry of the consumer host. With the offered information processing address and lease time. This information processing address won’t be provided by the server to the other host. The destination mac address is FFFFFFFFFFFF. And thus the destination information processing address is And also the supply information processing address is And thus the supply mac address is 00AA00123456 (server mac address).

DHCP discover message 

This is a primary message generated within the communication method. Between server and consumer. This message is generated by the consumer host so on getting. If there’s any DHCP server/servers area unit gift in a network or not. This message is broadcast to all or any devices gift in a network to search out the DHCP server. This DHCP discover message is  about 342 to 576 bytes long

source mac address (client PC) is 08002B2EAF2A, destination raincoat address(server) is FFFFFFFFFFFF. The supply information processing address is zero.0.0.0. (Because laptop has no information processing address until now). And destination information processing address is (IP address used for broadcasting). Because the discover message is broadcast to search out out the DHCP server. Or servers within the network thus broadcast information processing addresses. And mac address is employed.

DHCP release

A DHCP consumer sends a DHCP release packet to the server. To unharness information processing address and cancel any remaining lease time.

DHCP request message

When a consumer receives a supplied message. It responds by broadcasting a DHCP request message. The consumer can turn out a  gratuitous Hans Arp so on the search out if there’s the other host available. Within the network with the same information processing address. If there’s no reply by an alternative host, then there’s no host with the same TCP configuration. Within the network and thus the message is broadcasted. To server showing the acceptance of information processing address. A consumer ID is additionally added during this message.

Now, the request message is broadcast by the consumer laptop. Thus supply information processing address is (As the consumer has no information processing right now). And destination scientific discipline address is (Broadcast information processing address). And supply mac address is 08002B2EAF2A (PC raincoat address. And destination mac address is FFFFFFFFFFFF.

Note – This message is broadcast once the Hans Arp request is broadcast. By the laptop to search out out whether the other host isn’t utilizing. That offered information processing. If there’s no reply, then the consumer host broadcasts the DHCP request message. For the server showing the acceptance of the information processing address. An alternative TCP/IP Configuration.

DHCP decline

If DHCP consumer determines the offered configuration parameters are distinct. Or invalid, it sends a DHCP decline message. To the server. When there’s a reply to the gratuitous Arp by any host to the consumer. The consumer sends a DHCP decline message. To the server showing the offered information processing address is already in use.

Why use DHCP?

Every device on a TCP/IP-based network should have a novel unicast IP address. To access the network and its resources. While not DHCP, information processing addresses. For brand spanking new PC or computers that are touched. From one subnet to a different should be designed. Information processing addresses for computers. Those that are far from the network should be rescued.

With DHCP, this whole method is automated and managed. The DHCP server maintains a pool. Of information processing addresses associate degreed leases an address. To any DHCP-enabled shopper once it starts informing the network. As a result of the information processing addresses. Are dynamic (leased). Instead of static (assigned). Addresses not in use come to the pool for reallocation.

The network administrator establishes DHCP servers. That maintains TCP/IP configuration info. And supply address configuration to DHCP-enabled shoppers. Within the type of a leased supply. The DHCP server stores the configuration info in very info that includes:

  • Valid TCP/IP configuration parameters for all shoppers on the network.
  • Valid scientific discipline addresses are maintained in a very pool. For assignment to shoppers, furthermore as excluded addresses.
  • Reserved information processing addresses related to specific DHCP shoppers. this enables consistent assignment of one information processing address to one DHCP shopper.
  • The lease period, or the length of your time that the information processing address is used. Before a lease renewal is needed.
  • A DHCP-enabled shopper, upon acceptive a lease supply, receives:
  • A valid information processing address for the subnet to that it’s connecting.
  • Requested DHCP choices, that are further parameters. That a DHCP server is designed to assign to shoppers. Some samples of DHCP choices are Router (default gateway), DNS Servers, and DNS domain name.

Advantages of using DHCP

DHCP provides the after advantages.

Reliable information science addresses configuration. The DHCP minimizes configuration errors. Which are caused by manual information processing address configuration. Such as typographic errors, or address conflicts caused. By the assignment of an information processing address. To quite one pc at constant time.

  • Reduced network administration. DHCP includes the after options to scale back network administration:
  • Centralized and automatic TCP/IP configuration.
  • The ability to outline TCP/IP configurations from a central location.
  • The ability to assign a full variety of further TCP/IP configuration values utilizing DHCP choices.
  • The cheap handling of information science address changes. For purchasers that have to be updated oftentimes. Such as those for moveable devices that move. To distinct locations on a wireless network.
  • The redirecting of initial DHCP messages by utilizing a DHCP relay agent. That eliminates the need for a DHCP server on each subnet.

The disadvantage of using DHCP

The disadvantage of using DHCP

  • It may cause some IP conflicts.


That’s all about What is DHCP (Dynamic Host Configuration Protocol).  DHCP helps to cut back the typographic errors arising. Once information processing address configuration parameters aren’t outlined. Since each device should have a novel information processing address. Duplicate addresses will produce conflict.

Wherever one or each of the devices cannot connect with the network. DHCP minimizes the chance of such information processing addressing conflicts. If a modification is detected, the DHCP server is updated with new info. And thus the data is distributed to the new endpoints. Hope this helped you. For any query or suggestion feel free to use the comment box.


Q 1. What will Dynamic Host Configuration Protocol DHCP do?

Ans. Dynamic Host Configuration Protocol (DHCP) may be a client/server protocol. That mechanically provides an Internet Protocol (IP) host with its informatics address. And alternative connected configuration info. Like the subnet mask and default entry.

Q 2. When should I use DHCP?

Ans. The primary reason DHCP is required. Is to change the management of information processing addresses on networks. No two hosts will have a similar information processing address. And configuring them can cause errors.

Q 3. How does DHCP assign IP addresses?

Ans. The server replies to the consumer with a DHCP. Supply packet containing an information processing address. The consumer receives and validates the supply. Then send a call for a participation packet. Back to the server to accept the address. The server sends an acknowledgment packet back to the consumer. To verify the chosen information processing address.

Q 4. Should I use NAT or PAT?

Ans. A dynamic NAT affiliation, like a PAT affiliation. Is beneficial once trying to attenuate. The amount of public information processing addresses needed for connections. As a result, you’ll be able to assign many devices. To constant public information processing address utilizing ports. PAT connections cut back the depletion of public information science addresses.
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