What is DHCP

What is DHCP

• Dynamic Host Configuration Protocol
• It helps to get IP Address Dynamically from the Server.
• It works under the Process called as DORA
• D - Discover
• O - Offer
• R - Request
• A - Acknowledge
• DHCP uses Bootstrap Protocol to do DORA Process.
• DHCP Port Numbers :
• DHCP Server Port no : 67
• DHCP Client Port no : 68

DORA Process

• Discover
• Since Client doesn't know where is the Server, Initially it sends a broadcast frame with the destination mac as : ff.ff.ff.ff.ff.ff with its own source Mac and Source IP Address as 0.0.0.0 and destination IP Address as 255.255.255.255 (Broadcast IP Address).
• You can also see port no source port number as 68( DHCP Client Port number) and port number as 67( DHCP Server port number), which means from Client to Server.

• OFFER
• As soon as Server gets the information from the Client, it responds to the Client with certain details as Lease time, Broadcast IP, DNS IP, Subnet-mask, and its own information(MAC Address and IP Address ). 
• With these information, what it asks to the client as, I am having these information and this is my IP segment, is it Ok for you to use this IP Network range....

• Request
• Request is the Process from Client to Server, in response to DHCP-Offer.
• In this Process, Client request's to Server as, Can I use this IP Address (Here is 192.168.43.94).
• At this Stage also, Client doesn't have any IP Address.

• Acknowledge 
• This is the Final Step of the Process, here Server Acknowledges the Request send by Client as Ok, you can use this IP Address. 
• Server stores certain Information about a Client, you can see about this in the below images. 

This is the Final verification of DHCP Server.

That's it about DHCP

You can also Look into my Video Tutorial:

If you have any queries Kindly give a comment.....