Dynamic Host Configuration Protocol
DHCP

Dynamic Host Configuration Protocol (DHCP) is a protocol for assigning dynamic IP addresses to devices on a network. With dynamic addressing, a device can have a different IP address every time it connects to the network. In some systems, the device's IP address can even change while it is still connected. DHCP also supports a mix of static and dynamic IP addresses.

How does DHCP work.

DHCP is based on a client-server model and based on discovery, offer, request, and acknowledgment .DHCP port number for server is 67 and for the client is 68. It is a Client server protocol which uses UDP services. IP address is assigned from a pool of addresses. In DHCP, the client and the server exchange mainly 4 DHCP messages in order to make a connection, also called DORA process, but there are 8 DHCP messages in the process.

DORA is nothing but a sequence of messages which is exchanged between the DHCP Server and Client. DORA stands for mentioned messages :

·         Discover

·         Offer

·         Request

·         Acknowledgment

Now, take a look on this image. This image will clear the sequence of different messages which is used in DORA Process.

Advantages – The advantages of using DHCP include:

·         centralized management of IP addresses

·         ease of adding new clients to a network

·         reuse of IP addresses reducing the total number of IP addresses that are required

·         simple reconfiguration of the IP address space on the DHCP server without needing to reconfigure each client,The       DHCP protocol gives the network administrator a method to configure the network from a centralized area.

              With the help of DHCP, easy handling of new users and reuse of IP address can be achieved.