What is DHCP Server Configuration

 

6.1. DHCP SERVER

Dynamic Host Configuration Protocol (DHCP) is a client-server technology that allows DHCP servers to assign, or lease, IP addresses to computers and other devices that are enabled as DHCP clients.

When you deploy DHCP servers on your network, you can automatically provide ip address on client computers.

 

What Is DHCP?

DHCP uses a client-server relationship to allocate addresses, track their usage, and reclaim a

Predetermined list of IP addresses and other configuration information shared in a network of

Systems. Each organization has one or more DHCP servers with a range of predefined IP addresses, as well as other startup information or additional parameters. When a user boots a client system, that system broadcasts a request for a DHCP server to issue it an IP address.

 

6.2. Where DHCP Is Useful :-

The most common usage of DHCP is to move the management of IP addresses away from the distributed client systems and onto one or more centrally managed servers. These central servers maintain databases of parameter information (addresses, netmasks, and so on) eliminating the need for clients to store static network information on their machines. This specifically obviates the need to configure TCP/IP parameters into client machines. Since most client systems now ship from the factory with dynamically assigned IP addresses as the default configuration, the user need only boot the machine to be up and running with the TCP/IP protocol. This approach saves time configuring or debugging the network environment, reducing the cost of ownership for client systems.

 

DHCP is particularly useful in the following environments:

• Sites that have many more TCP/IP clients than network administrators.

   By using DHCP, managers can more effectively manage a large community of client systems.

• Sites where laptops commonly move among networks within the site. By using DHCP, laptop

users can plug into the network at any location, and use a local DHCP-assigned IP address to

communicate with the local systems.

 

6.3. Let’s We Make a DHCP Server

open configure your server wizard

 

scroll down to DHCP server and click next

The wizard will probably copy some files from the Windows 2003 server CD

Next we need to configure our scope (New Scope Wizard)

Don’t bother to add any exclusions (just click next)

 

Leave the lease duration as default, and next select No. I will configure these options later for the DHCP scope option

You should now see this

Click Finish

Now we need to activate the scope, click on Start/All Programs/Administrative tools/DHCP

right click on the highlighted scope and choose activate then

right click on the DHCP server with the red mark above the scope, and choose Authorize

Once done you should now have the DHCP server scope activated and the DHCP server authorized in active directory. If the DHCP server doesn’t appear green hit the refresh button a few times.

ok your DHCP server is ready to use 

6.4. Automatic Private IP Addressing (APIPA) is a functionality that allows a computer to automatically assign itself a dynamic IP address – even though no DHCP server is available on the network. This will only occur if no static IP has been provided for the computer. APIPA uses a range from 169.254.0.0 – 169.254.255.255 with a subnet mask of 255.255.0.0 (/16) – meaning that we are dealing with a class B network with the maximum of 65.534 hosts. No default gateway or DNS is set by APIPA, so only limited local communication is available.

With Windows XP we got a new tab on the NIC’s TCP/IP settings called “Alternate Configuration”. This tab is only available, if no static IP has been entered on “General” tab

Here you will notice that the “Alternate Configuration” tab is missing because the IP has been statically assigned by an administrator. What this does is that if no DHCP service is found on the network, then the Alternate configuration will be used – this could be “Automated private IP address” (APIPA) or a “User configured” configuration (a static IP assignment).