Networking: IP Address vs DNS vs DHCP

What is IP Address?

An Internet Protocol Address (IP address) is a numerical label assigned to each device (e.g., computer or printer) participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principle functions: host or network interface identification and location addressing.

What is DNS?

The Domain Name System (DNS) is the Internet’s primary naming system for computers, services, or any resource connected to the network. It translates the numerical IP used by electronics, to Domain Names that can be easily be memorized and recognized by humans worldwide. In other words, DNS is a server that matches IP addresses with Domain Names.

What is DHCP?

The Dynamic Host Configuration Protocol (DHCP) is a network protocol that enables a server to automatically assign an IP address to a computer from a defined range of numbers (ie. a scope) configured for a given network. With DHCP, computers request IP address and networking parameters automatically from a DHCP server, reducing the need for a network administrator or user to configure these settings manually.

Dynamic Host Configuration Protocol (DHCP) assigns an IP address when a computer or system is started. For example:

1. A user turns on a computer with a DHCP client.
2. The client computer sends a broadcast request (called a DISCOVER or DHCPDISCOVER), looking for a DHCP server to answer.
3. The router directs the DISCOVER packet to the correct DHCP server.
4. The server receives the DISCOVER packet. Based on availability and usage policies setting on the server, the server determines an appropriate address to give to the client. The server then temporarily reserves the address for the client and sends back to the client an OFFER (or DHCPOFFER) packet, with that address information. The server also configures the client’s DNS server, WINS servers, NTP servers, and sometimes other services as well.
5. The client sends a REQUEST (or DHCPREQUEST) packet, letting the server know that it intends to use the address.
6. The server sends an ACK (or DHCPACK) packet, confirming that the client has been given a lease on the address for a server-specified period of time.

When a computer uses a static IP address, ti means that the computer is manually configured to use a specific IP address. One problem with static assignments, which can result from user error or inattention to detail, occurs when two computers are configured with the same IP address. This makes a conflict that results in loss of service. Using DHCP to dynamically assign IP addresses minimizes these conflicts.

Switches connect your network, computer, printers, servers, routers, etc. together. Switches have protocols that tell them where to take & deliver data streams….