Dynamic Host Configuration Protocol(DHCP)

Dynamic Host Configuration (DHCP) assigns IP addresses to hosts. It allows easier administration and works well in small to even very large network environment. All types of hardware can be used as a DHCP server, including a Cisco router.

DHCP server can provide to a host when the host is requesting an IP address from the DHCP server. Here's a list of the information a DHCP server can provide:

a) IP address

b) Subnet mask

c) Domain name

d) Default gateway(routers)

e) DNS

f) WINS information

 

A DHCP server can give us even more information than this, but the items in the lists are the most common

A client that sends out a DHCP Discover message in order to receive an IP address sends out a broadcast at both layer 2 and layer 3. The layer 2 broadcast is all Fs in hex, which looks like this : FF:FF:FF:FF:FF:FF. The layer 3 broadcast is 255.255.255.255, which means all networks and all hosts. DHCP is connectionless, which means it uses User Datagram Protocol(UDP) at the Transport layer, also known as the Host-to-Host layer.