Dynamic Host Control Protocol (DHCP) information. Enabling plug-and-play networks.
What is DHCP?
DHCP is an acronym for Dynamic Host Configuration Protocol. DHCP is the method in which hosts or clients of a network are allocated IP addresses automatically. Prior to DHCP, network administrators were forced to manually configure the IP address for each device on a network. DHCP is known by many to be a plug-and-play protocol, because it allows for IP address assignment to occur automatically and without intervention by administrators. In addition to IP address assignment, DHCP also provides clients of a network the ability to get information such a the subnet mask, the default gateway, and the IP address of the local DNS server.
DHCP on Local Area Networks – An Example
When you go to your favorite coffee shop and connect to the free Wifi offered to customers, what determines your IP address? With DHCP, the network automatically assigns you a temporary IP. Imagine how many people connect to and disconnect from the same Wifi hotspot on any given day. DHCP allows their IP assignment to occur automatically. Otherwise, a network administrator would have to manually assign and unassign a new IP address upon each and every connection and disconnection.
This allows your laptop or mobile device to communicate with the rest of the World Wide Web from any location. How? Well, lets say you leave that network, go home, and connect to the Internet. More than likely, your computer will get an entirely different IP address thanks to DHCP.
Internet Service Providers Use DHCP Too
DHCP is a protocol that uses a client-server model. That just means that there is one central device that helps to manage multiple other devices. Your Internet Service Provider likely uses this model to implement DHCP for its residential customers. Just like the coffee shop example above, ISPs assign IP addresses to a device each time it connects to a network.
When you connect your modem to the ISPs network, your modem is assigned an IP address. For most residential Internet users, this IP address is what is referred to as dynamic or sticky. This means that if you disconnect your modem from the Internet, you’ll get a new IP address the next time you re-connect.