How Do Dhcp Servers Respond To A Dhcpdiscover Message?
Share
Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
How do DHCP servers respond to a DHCP discover message?
Before we discuss the DHCP, let us know to look at an example of the TCP/IP network configuration. By taking windows as the example let us start a window command prompt and type IP config/all and press enter.
After pressing enter we can see the computer’s physical address, IP address, subnet mask lease obtained. We can use these configuration credentials for a couple of days. We can also see the IP addresses of the default gateway, DHCP server, and DNS servers. These are useful for connecting the Internet. Now let us know how does the computer or more specifically the wireless adapter gets this network connection information.
The DHCP stands for Dynamic host configuration protocol that allows the DHCP server to set the TCP/IP network automatically and for the configuration of the client computer. Without the presence of the DHCP technology, we can set up all the configuration values manually by the computer. And this process of setting up the client computer is called static addressing. We can know the difficulty if we do not use the DHCP network.
Now let us know how the DHCP works. When the client computer boots up in the broadcast DHCP discover the message it doesn’t matter how where the client computer is present. It may be at home or at an unknown location. It would send the packet by looking for the DHCP server. If the client has no idea that there is a DHCP server present nearby, then the broadcast is the only way to notice the destination IP address. The DHCP discover packet asks if there is any DHCP server present out there and informs that it wants to connect to the Internet.
And coming to the next step, if there is any DHCP server present close by and if it hears the DHCPDiscover message then the DHCP server responds by sending a message called the DHCPOFFER message. The DHCPOFFER is a broadcast UDP packet. It simply replies as it heard the message and tells that it can lease the IP address. And we can connect to the local network. It also tells the IP address of the default gateway and the DNS servers so that we can go to the Internet.
Coming to another step, the DHCP client responds with the DHCPREQUEST. It says that it accepts all the TCP/IP information and the lease term.
And in the next step, the DHCP server replies to the DHCPACK message. It is nothing but the acknowledgment packet. It says OK and tells to use the network and register the MAC address or the other information in the DHCP database. And this is the process of the DHCP.
The DHCP is the dynamic way of giving the client computer network connection credentials between the DHCP servers. And the clients have broadcast UDP and not in the TCP. The client uses port 68 and the server can use port 67. Type the IP config/release and then reload a browser, if you are using windows. We can see it as the no internet connection. Now type IP config/renew now we can see that the internet is back.