ARP Protocol

We have two identifiers: MAC address and IP address

The #ARP or Address Resolution Protocol is the technology that is responsible for allowing devices to identify themselves on a network

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Simply, the #ARP protocol allows a device to associate its MAC address with an IP address on the network. Each device on a network will keep a log of the MAC addresses associated with other devices

Devices can use the ARP protocol to find the MAC address of a device for communication

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How does this Protocol Work??

Each device within a network has a ledger to store information on, which is called [[cache]]

In the context of ARP protocol, this cache stores the identifiers of the other devices on the network which are [[IP Address]] and [[MAC Address]]

In order to map these two identifiers together, the ARP protocol sends two types of messages

1. ARP Request

   1. When an ARP Request is sent, a message is broadcasted to every other deice found on a network by the device, asking whether or not the devices MAC address matches the requested IP address

   2. If the device does have the requested IP address, an ARP reply is returned to the initial device to acknowledge this.

   3. This initial device will now remember this and store it within its cache - #ARP_Entry

2. ARP Reply

[[Pentester Notes/Protocols/DHCP Protocol|DHCP Protocol]]