A Full Introduction to ARP (Address Resolution Protocol)

What Is ARP

What is ARP? ARP is the abbreviation of Address Resolution Protocol. It is a protocol or program that connects a constantly changing Internet Protocol (IP) address to a fixed physical machine address in a local area network (LAN), also known as a media access control (MAC) address. Now, you can continue to read this post from MiniTool to get more information about ARP.

Why You Need ARP

ARP is necessary since the software address (IP) of the host or computer connected to the network needs to be converted to a hardware address (MAC address). Without ARP, the host will not be able to find the hardware address of another host. The LAN reserves a directory that maps IP addresses to different devices, including MAC addresses and hosts on the network.

How Does ARP Work

How does ARP work? When a new computer joins the LAN, it will be assigned a unique IP address for identification and communication. The data packet arrives at the gateway, and the destination is a specific host.

The gateway or hardware on the network that allows data to flow from one network to another requires the ARP program to find a MAC address that matches the IP address. The ARP cache records each IP address and its matching MAC address. The ARP cache is dynamic, but users on the network can also configure a static ARP table containing IP addresses and MAC addresses.

The ARP cache is stored on all operating systems in the IPv4 Ethernet network. Every time a device requests a MAC address to send data to another device connected to the LAN, the device verifies its ARP cache to see if the IP-to-MAC address connection has been completed. If it exists, no new request is required. However, if the conversion has not been performed, a request for the network address is sent and ARP is performed.

Types of ARP

ARP has different types. Now, let’s see the details about the types of Address Resolution Protocol.

Proxy ARP

The first type of ARP is proxy ARP. Proxy ARP is a technology through which a proxy device on a given network responds to ARP requests for IP addresses that are not on the network. The proxy knows the location of the traffic destination and provides its own MAC address as the destination.

Gratuitous ARP

The second type of ARP is Gratuitous ARP. It is almost like a management program, implemented as a way for hosts on the network to simply announce or update their IP to MAC addresses. An ARP request that converts an IP address to a MAC address will not prompt for gratuitous ARP.

Reverse ARP (RARP)

The third type of ARP is RARP. Hosts that do not know their IP address can be discovered using Reverse Address Resolution Protocol (RARP).

Inverse ARP (IARP)

The last type of ARP is IARP. Whereas ARP uses an IP address to find a MAC address, IARP uses a MAC address to find an IP address.

Now, here is all information about types of ARP.

ARP VS DHCP VS DNS

Next, let’s see the differences between ARP, DHCP, and DNS.

ARP is the process of connecting a dynamic IP address to the MAC address of a physical machine. As mentioned earlier, IP addresses are designed to be constantly changing for a simple reason. Doing so provides users with security and privacy.

However, the IP address should not be completely random. There should be rules for assigning IP addresses from a defined range available in a particular network. This helps prevent problems, such as two computers receiving the same IP address. These rules are called DHCP (Dynamic Host Configuration Protocol).

The IP addresses that are the identity of the computer are important because they are required to perform Internet searches. When you search for domain names or uniform resource locators (URLs), they use alphabetic names.

On the other hand, computers use numeric IP addresses to associate domain names with servers. To connect the two, a Domain Name System (DNS) server is used to convert the IP address from a confusing string of numbers to a more readable.

Final Words

Now, it’s time to make a conclusion. You can know the definition, importance, work principle, as well as the types of ARP. Besdies, you can know the differences between ARP, DHCP, and DNS. I hope that this post can be helpful to you.