Get wired connected clients

[Raul Macarie]

I'm trying to get a list of all connected clients, for wireless network i'm using: wl -i eth1 assoclist & wl -i eth2 assoclist, and for VPN i'm using cat /etc/openvpn/server1/status, but i've haven't figured it out a way to get a list of clients that are connected using the LAN ports. I've tried arp -a but it's unreliable, it doesn't always show me an accurate list. The reason i need this is because on one of the LAN ports i've connected a POE switch, and on that switch there are some IP cameras, and i need to know if one of those cameras gets disconnected for some reason.