What is DHCP(Dynamic Host Configuration Protocol)?

What is  DHCP (Dynamic Host Configuration Protocol)

If a host wants to communicate with another host in any network, then its pass must be a unique IP address. Whether it is LAN (Local Area Network) or WAN (Wide Area Network). You can also configure these IP addresses manually on each host.

But if the network is large enough then this approach will not work. In large networks you cannot manually assign IP addresses by going to each host pass. DHCP is used to solve this problem.

What is  DHCP(Dynamic Host Configuration Protocol)?
DHCP client&server:What is  DHCP(Dynamic Host Configuration Protocol)?

DHCP definition

DHCP is a Network Protocol that is used to automatically provide IP addresses in a defined range (Scope) to networked computers connected to the server.

The task of Dynamic Host Configuration Protocol is to assign IP addresses to hosts. These IP addresses are assigned dynamically. DHCP always maintains a pool of IP addresses. As soon as a host tries to connect to the network, it requests an IP address from DHCP.

DHCP assigns an IP address to the host's request. When the host leaves the network, this IP address returns to the DHCP pool and becomes available to other hosts.

What is  DHCP(Dynamic Host Configuration Protocol)?
What is  DHCP(Dynamic Host Configuration Protocol)?

When a network computer starts and the computer has a DHCP Client service, that client checks whether the computer has a static IP address or the computer has a DHCP setting. If the computer has a DHCP setting, then the computer requests the IP address from the DHCP server through the DHCP Client service. When the server receives a request, after checking the validity of that computer, according to its defined range and scope, reserving an IP address and sends it to that computer. Thus the network computer gets the IP address

DHCP is a client / server protocol. Its port number is 67.

Providing an IP address to hosts is the primary task of DHCP. But DHCP provides many information hosts besides IP address. A list of some such common information is given below.

IP address (Ex.
Subnet Mask (Ex
Domain Name (Ex. Www.yourdomain.com)
Default Gateway (Ex.
DNS Server Address
Advantages of DHCP (Dynamic Host Configuration Protocol)
Now let's try to know what advantages you get from DHCP.

DHCP reduces the chances of errors in IP address configuration.
Using DHCP does not require you to manage the IP address list. Also you do not need to manage which IP address is free and which has been assigned. DHCP does this work automatically.
If you move the host to another network, DHCP assigns a new IP address.

Advantages of DHCP

Reliable IP address configuration - When DHCP is used in a network, it reduces IP configuration errors compared to manual IP configuration such as typographical errors, IP address duplication etc.

Saves time in network administration: By doing DHCP configuration in a network it reduces the manual tasks of system and network administrator.Because it does centralized and automated TCP / IP configuration to clients.

Updates the IP address of the clients easily at the schedule time.

What is  DHCP(Dynamic Host Configuration Protocol)?
DHCP header:What is  DHCP(Dynamic Host Configuration Protocol)?

Process of IP Address Configuration with DHCP

There are a few steps from the request of the host to the process of assigning an IP address. These steps are explained below.

First, DHCP client (host) broadcasts DHCP discover message for available DHCP servers. It is used to discover the DHCP server in the message network.

After this, the DHCP server that receives this message sends an offer message to the client. The DHCP server shows its own existence through the offer message.

The client then broadcasts the request message to the IP address and regarding information to the server.The server then sends the information to the client via an unicast acknowledgment message.

Configuring DHCP (Dynamic Host Configuration Protocol)

DHCP server has an important role in any network. The DHCP server can be configured on any router or switch. If you are configuring DHCP server then you should have the information given below.


You must have a pass network ID. If you do not define the network ID of a subnet, then by default all the addresses are assigned.

You should also know what are the addresses that are already being used. Such as any addresses that are being used for printers, routers or other purposes. Such addresses are exclude from the DHCP configuration.

You should also know the address of the network's default router (default gateway).

You should also know the address of the DNS (Domain Name System) server.

What is  DHCP(Dynamic Host Configuration Protocol)?
DHCP procrss :What is  DHCP(Dynamic Host Configuration Protocol)?

The information mentioned above is required to configure any DHCP server. Some steps are given to configure the DHCP server below. You can easily configure DHCP by following these steps.

First of all, you exclude addresses that are already being used or reserved for another purpose.
After that you create a pool with unique name for the subnet.
After this you set the network ID and subnet mask that the server hosts will use to assign IP addresses.
After this you set the address of the default gateway.
After this the address of the DNS server is set.
If you do not want to use already set lease time, then you can set the lease time in days, hours and minutes.


Below is an example of DHCP configuration.

router (config) #ip dhcp excluded-address
router (config) #ip dhcp pool Best_Hindi-Tutorials
router (dhcp-config) #network
router (dhcp-config) # default-router
router (dhcp-config) # dns-server
router (dhcp-config) #lease 2 15 2
Look at the example above carefully, first the network Id and the broadcast address are exclude. After this a DHCP pool has been created named Best_Hindi_Tutorials.

After this the network and subnet mask is defined. Network is defined by network Id. After this the default gateway and DNS server are defined.

Dynamic vs Statics DHCP

A client does not have the allocated IP address with dynamic DHCP, but rather "leases" it for a period of time. Another IP address must be rented by means of a DHCP server every time a machine with a dynamic IP address is uploaded. Users that connect to a network are provided with wireless devices as example of dynamic IP addresses.

Static IP address assignment systems have constant IP addresses and are used in equipment such as Web servers or switches.
A client may also be required to undertake certain actions under the dynamic DHCP configuration to terminate its IP address and then to reconnect to the network via a different IP address. DHCP lease periods can differ depending on the length of time a customer may need to connect to a certain place. Devices publish their DHCP rental IP addresses and then requeste the DHCP server renewal if they stay online. A new address may be assigned to the DHCP server as opposed to an old address.

A client receives a lease IP address via the DHCP server request delivery process.

If a client has a IP address of an current lease already, he or she will have to update its IP address when he or she boots back after shutdown.

The client shall be bound to the lease and the email once a lease is present.

After the lease has expired, a customer will contact the server which has originally renewed it to use their IP address.

If a client moves to another network, their dynamic IP IP address is suspended and a new DHCP IP address will be requested from the new network's DHCP server.

Thank you for reading the What is  DHCP(Dynamic Host Configuration Protocol)?

Also read :

No comments:

Post a Comment