DHCP Offer Message
DHCP server receives the discover message and it replays the DHCP client with the DHCP offer request. The server sends a DHCP offer message with filled information. It has information about the IP address and duration of time that a host can use. Here destination IP address will be 255.255.255.255 as the DHCP client still does not have its IP address. But this DHCP offer message is broadcast in the network layer and unicast in the data link layer.
Source IP address: IP Address of DHCP Server Destination IP address: 255.255.255.255 Source MAC address: MAC address of DHCP Server Destination MAC address: MAC address of DHCP clients
How DORA Works?
Dynamic Host Configuration Protocol(DHCP) uses the DORA. Dynamic Host Configuration Protocol is the protocol of the application layer. It is used to provide Subnet Mask, Router Address, DNS Address, and Vendor Class Identifier. In fact, DHCP provides an automatic IP address to Hosts which want to connect to a network.
DORA is the process that is used by DHCP. DORA helps in providing an IP address to hosts or client machines. DORA is the process that follows some steps between the server and client. It gets the IP address from the centralized server. It consists of four-stage:
- Discover
- Offer
- Request
- Acknowledge
Now let’s see what happens when DHCP clients request a DHCP server an IP address. Let’s see what messages are exchanged between them in the process.
Note: In the network layer, DHCP messages are always broadcast. In the data link layer also DHCP messages are broadcast.