Stepping through the DORA process
The DHCP process is an efficient way to provide addresses to clients. Because we want our IP address quickly, it uses User Datagram Protocol (UDP) as the transport layer protocol.
DHCP uses the following UDP ports:
- Clients use port
68. - Servers and relay agents use port
67.
DHCPv6 uses the following UDP ports:
- Clients use port
546. - Servers and relay agents use port
547.
You will see these ports in use when we examine DHCP traffic.
The DHCP process progresses through various states during a transaction, as outlined in the next section.
Moving through DHCP states
During the process of a DHCP transaction, the client can be in one of six states. Understanding these states and what transpires will help during troubleshooting. These DHCP states are as follows:
- Initiate: The client begins the process by sending a broadcast on the network in search of a DHCP server.
- Select: The client will select...
