1

i am a newbie but i need to understand this ARP thing.

In my company we have a router that has 3 switches connected to it. On the switches there are more than 100 hosts.

I know that switch learns and stores mac addresses but my question is, how does a router know mac addresses of hosts when switch doesn't store their ip addresses.

Thanks

Marko
  • 11
  • 1

1 Answers1

1

I know that switch learns and stores mac addresses but my question is, how does a router know mac addresses of hosts when switch doesn't store their ip addresses?

Switches have nothing to do with ARP. Only hosts with IP addresses participate in the ARP protocol.

Since ARP queries are broadcast, switches forward them out all ports. Presumably, the router is connected to one of those ports, so it hears the query and can answer if need be.

Ron Trunk
  • 68,291
  • 5
  • 66
  • 126