What is Dora process in DHCP and how it works?

1) Client makes a UDP Broadcast to the server with a DHCPDiscover, or Discover packet.

2) DHCP offers to the client.

The server sends a DHCPOffer including other configuration parameters (DHCP Options) for the client per the servers configuration file

3) In response to the offer Client requests the server.

The client replies DHCPRequest, unicast to the server, requesting the offered address.

4)The server sends DHCPAck acknowledging the request which is the clients final permission to take the address as offered. Before sending the ack the server double checks that the offered address is still available, that the parameters match the clients request and (if so) marks the address taken.

A good reference for DHCP information is Droms and Lemon "The DHCP Handbook". BoydK