Hi so my OPNSense LAN is 172.16.2.1 and the Switch connected to it (that has the subnets) with a LAN 172.16.2.2. I have, on OPNSense, 6 static routes to find 6 networks on 172.168.2.2. On the Switch I have 0.0.0.0 172.16.2.1 default route back for all networks to reach Internet.
All works fine. On the Switch, Cisco SG350XG my arp table has all 20-30 lan ips as it should. On OPNSense the ARP table just shows 172.16.2.1 and 172.16.2.2. I was curious if both the switch and OPNSense clearly communicate via the 172.16.2.0 Network, should the OPNSense also be able to see the arp table as well?
ARP is only for directly connected networks. Anything that is reached via another router is not visible in ARP.
Outside of 'ARP' is there any higher level type software or application that can see the network as a whole? I only pursue because the networks can all ping each other so there is a 'link' but again, may not be something that is done under normal circumstances.