DHCP

Dynamic Host Configuration Protocol (DHCP) - an application layer protocol that automates the configuration process of hosts on a network

a machine can query a DHCP server when the computer connects to a network, and receive all the networking configuration in one go
reduces administrative overhead of having to configure multiple network devices on a single network
helps address the problem of having to choose what IP to assign to what machine

Dynamic Allocation - a range of IP addresses is set aside for client devices and one of these IPs is issued to these devices when they request one

the IP of a computer can be different almost every time it connects to the network

Automatic Allocation - a range of IP addresses is set aside for assignment purposes

DHCP server is asked to keep track of which IPs it’s assigned to certain devices in the past
using this method, the DHCP server will assign the same IP to the same machine each time, if possible

Fixed Allocation - requires a manually specified list of MAC address and their corresponding IPs

when a computer requests an IP, the DHCP server looks for its MAC address in a table and assigns the IP that corresponds to that MAC address
if the MAC address is not found, the DHCP server might fall back to automatic or dynamic allocation, or refuse to assign an IP all together

Network Time Protocol (NTP) - used to keep all computers on a network synchronized in time

DHCP Discovery - the process by which a client configured to use DHCP attempts to get network configuration information

DHCP Discovery: DHCP client sends a DHCP discover message out onto the network
DHCP Offer: The DHCP server would examine its own configuration and would make a decision on what IP address (if any) to offer to the client
DHCP Request: DHCP client would respond to DHCP offer message with a DHCP request message
DHCP Acknowledgement: the DHCP server receives the DHCP request message and responds with a DHCP ACK or acknowledgement message