DHCP Server Basic

DHCP Server Basic 

What is DHCP Server?

       The Purpose of DHCP server in Network is to provide the TCP/IP Configuration to the Client. DHCP free up System Administrator from Manually configuring each host on the network. and quickly configure changes in a network configuration. And In The larger network, the greater benefit of using DHCP is that you do not need manually configure and maintain the record  Without dynamic address assignment, each host has to be configured manually and IP addresses must be carefully managed to avoid duplication or miss configuration.

      And Because settings and information are stored centrally, you can quickly and easily add or change a client setting (for example, the IP address of an alternate DNS server) for all clients on your network from a single location. Without a centralized database of configuration information, it is difficult to maintain a current view of the host settings or to change them.

DHCP provides five key benefits to those managing and maintaining a TCP/IP network:-

1. Centralized administration of IP configuration:- DHCP IP configuration information
   can be stored in one location, enabling the administrator to centrally manage it. A DHCP
   server tracks all leased and reserved IP addresses and lists them in the DHCP console. You
   can use the DHCP console to determine the IP addresses of all DHCP-enabled devices on
   your network.
2. Dynamic host configuration:- DHCP Server Automatically configure Host and update the changes dynamically.
3. Seamless IP host configuration: -The use of DHCP ensures that DHCP clients get accurate and timely IP configuration parameters, such as the IP address, subnet mask, default gateway, IP address of the DNS server, and so on, without user intervention. Because the configuration is automatic, troubleshooting of miss configurations, such as mistyped numbers, is largely eliminated.
4. Scalabilit :- As Scalability is censor  DHCP is Scala for both small and very large network.
5. Flexibility :- Using DHCP gives the administrator increased flexibility, allowing the
   administrator to more easily change IP configurations when the infrastructure changes.

It provide following information to client but not limited to it. It Provide more than 70 TCP/IP configuration settings.

• IP Address.
• Subnet Mask
• Default Gateway
• DNS Domain Name
• Address of DNS Server
• Address of WINS Server.
• And many more

How it Work ? OR DHCP Client And Server in DORA Process. 

      When you turn on DHCP on Client Computer to get TCP/IP information from DHCP Server. there are some communication will get between DHCP Client and DHCP Server. this process are called as DHCP DORA Process. DORA Means Discover, Offer, Request and acknowledgment .

1. Discover: -When you turn on DHCP on client computer to get TCP/IP information from DHCP server. because client do not having IP address information about DHCP server to get TCP/IP information .It send broadcasts packet in a network to find DHCP server who can give him TCP/IP information.
2. Offer: - If in network there are DHCP server running . All  DHCP server Responds to the broadcast by sending Offer Packet because Client do not having IP Address it also broadcasts back to client by offering TCP/IP configuration. (DHCP server ask Client for confirmation that it is ready to accept the offer else that IP address will be provided to other clients.)
3. Request : - So Client computer responds with first DHCP offer by sending  Request Packet. for acceptance and because other Server not got any confirmation by client it know that client has not accecpted our offer so we can be able to give ipaddress to other client.DHCP Request packet are  uni cast packet because now client know IP address of DHCP server to contact. 
4. Acknowledgment :- After receiving  the request packet DHCP Server send Acknowledgment packet to client that it can use this IP address .

(In next post we will see how to install, Configure and backup DHCP server in windows 2003 and 2008 server)