computer networking: ARP - point of the ICMP echo

Question

I'm studying Address Resolution Protocol and in all my books and slides the diagrams showing an ARP take place (i.e. Host1 sends ARP request, Router checks it, redirects it, eventually gets to Host2 and then Host2 sends back an ARP Reply).

What I'm wondering is why the examples include ICMP echo replies and requests, do they serve any purpose within ARP?

Thanks

Answer 1

I would guess that it is to initiate the ARPs. A machine is not going to send an ARP for no reason. It will only send an ARP if it needs to send something to the IP address (and doesn't know the destination MAC address yet). Maybe the ICMP echo request is that 'something' the authors use in their examples to cause the source machine to send an ARP.

Short answer: There is no special relationship between ICMP and ARP; that's just what the authors of your book decided to use as an example.