Please let me start by saying I am no network expert, I am a programmer who does a fair amount of L3/4 programming.
My question is that when a switch receives a packet with a destination MAC that is not found in its table arp table for whatever reason. What is the action performed? do they send an arp? send the packet on all output interfaces?
Best Answer
ARP resolves IP addresses to MAC addresses. Switches don't ARP for traffic sent from one host to another host. As such you wouldn't find an entry for the destination host in the switch's ARP table unless the switch itself is trying to communicate with that destination host.
What you're looking for is the switch's MAC address table, which is it's MAC address to port table, which tells the switch which MAC address is accessible via which port.
In the case where the switch's MAC address table doesn't have an entry for the destination host the switch will flood/forward the frame to all ports. Note that I didn't use the term broadcast as this is not a broadcast. Unicast traffic is flooded in this scenario, broadcast traffic is broadcasted.