All you need to know about ARP…

Address Resolution Protocol (ARP):used to match IP address with Mac address.

All layer 3 devices have ARP table (ARP cache) and use ARP.

ARP happens in LAN (Ethernet network)

ARP requests are L2-broadcast, ARP responses are L2-unicast

Here are the process:

Ethernet is a layer 2 protocol

Ethernet frames need a destination address

If the destination mac is in your ARP table, you can send the frame

If it isn’t, you send a broadcast ARP request to find the mac address

If the destination host is in your subnet, you can send the frame directly

If the destination host in in another network, you have to send the frame to your default gateway

You send the frame to the gateway’s mac address

The default gateway is a router

Routers make decision based on layer 3 IP addresses

Routers de-encapsulate the frame to see where they have to send it next…

On an Ethernet network, the router sends the frame to the next mac address…

Watch more:

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