In the example below, the ARP request is flooded on all ports by the switch.If the host to which the source IP belongs to exists on the local network, then an ARP Reply message is sent back. If the Layer-3 destination IP address belongs to the same local network as the source IP address, then the host sends out an ARP Request to the Layer-2 broadcast address (FF:FF:FF:FF:FF:FF). Before sending a packet, a host consults its ARP cache: a table that contains mappings of all known IP and MAC addresses. In other words, ARP enables hosts to insert the correct Destination MAC Address in the Layer-2 Frame, in order to reach the more universally recognized Destination IP Address in the Layer-3 Packet.

Table of Contentsĭevices use the Address Resolution Protocol (ARP) to discover other hosts on the network by mapping the hardware address to the destination IP address that is being reached.

NOTES: Find a complete introductory guide on Routing and Switching in our Ubiquiti Broadband Routing & Switching Specialist (UBRSS) guide, downloadable in our Training section.

Arp network mac address broadcast