This particular chapter is about the DHCP server. DHCP stands for Dynamic Host Configuration Protocol. This tutorial is going to teach you all about DHCP router i.e. overview, troubleshooting tips, debugging, sub netting and Internet Protocol addressing. DHCP or Dynamic Host Configuration Protocol is network protocol assigning advanced technique through which Internet Protocol addresses are assigned to the computers automatically which connects with the network anytime. The time and effort taken in assigning the Internet Protocol address to the client computers individually can be saved by using a DHCP server. DHCP assigns the IP addresses from the provided range of the numbers from the manufacturer. These ranges of numbers are also called DHCP scope.
We discussed about the router end that how DHCP works there now we will discuss about the client or user end. Client computers or the user’s machines are configured by their operating system with such a technique that they are configured automatically without any effort. Not only configuring the Internet Protocol address the Dynamic Host Configuration Protocol can also assign the DNS and WINS server address.
When a computer starts up it gets the IP addresses from the DHCP server from the defined pool of addresses.
Assigning of IP address through DHCP server is a process. The steps of this process are the following:
- First the user has to enable the DHCP server client on his computer.
- There is a broadcast request known as DHCP DISCOVER which is sent by the client computer to the DHCP server router and then wait for the DHCP server to answer the request.
- The DHCP server when receives the DHCP Discover request which is based on the settings and availability defined by the user’s operating system. The server then chooses any available IP address free in the range of number provided to it by the manufacturer (from DCHP scope) and assign it to the requesting user’ computer. This particular step is collectively known as the answer to DHCP Discover or the DHCP OFFER. The DHCP offer contains the Internet Protocol address provided by the DHCP server.
- In the next step the client or the user’s computer again send a request to the DHCP server which is known as DHCP REQUEST in which the client confirms that it is using the IP address provided by the DHCP server.
In the next step the DHCP server again confirms the acknowledgment of the IP address assigned to the computer for a given time of period. This confirmation is known as DHCP ACK.
These steps above are collectively known as DHCP DORA (Discover, Offer, Request and Acknowledgment).
Many computers uses static IP addresses assigned by the DHCP server in which there are chances of IP address conflict but when you are using a DHCP server there are no chances of IP address conflict.
Along with the IP addresses, the DHCP server also enables the client computers to extract all the settings and configurations from the DHCP server on an IP network. These settings include the Firewall, Router, DNS, and Nat, WINS, Gateway and Subnet masks settings.
The basic purpose of the DHCP server is to reduce the work load and the time taken by the man to assign IP addresses to the users and troubleshooting it. The IP addresses assigned by the DHCP server to the clients area for a temporary or a limited time period and when that time period end the client computer has to confirm that it is still using this IP address and if you want to renew or change your IP addresses then you will have to type the following commands in the command prompt i.e. IPconfig/release to release the IP address then IPconfig/renew to gain a new IP address. The current IP address would be lost and may be assigned to another machine and a new free IP address is given to the specific computer.
Some IP addresses are reserved which are called Reserved IP addresses and they are assigned to the MAC or the home-stone clients which are fixed users or clients.