Quick Question

If show cam dynamic does not show the MAC then the device has not "recently" sent data through the port. Can you ping the device, or reboot it, or otherwise prod it to use the network? If that isn't practical, then you may wish to consider spanning the port to another and using a program such as arpwatch or tcpdump to monitor for the MAC.

I see thanks. Is there way i can actualy ping a port? Because since i have no idea where the device is with out tracing the wire i cant find it. And i willl try span the port and just monitor it but thats still pasif is there an active method. Can i flood the port with a request dhcp or arp. Is there a way to flood a port?

Thanks againe

Sorry, no.

Every broadcast or multicast packet is automatically flooded to every port that is in the same VLAN. However, whether the device will bother to respond is not under your remote control.

You could *try* pinging 255.255.255.255, or you could *try* sending a UDP packet to the broadcast address of each subnet it might be on, in hopes that the device will choose to respond to something, but there is no certainty: even without any "firewall" at any level, it is not uncommon for systems to only respond to traffic to their IP (or their MAC.)

Does the device definitely have an IP address, in a known range (even if the exact IP is unknown)? If so then you could use any of a number of tools to sweep through the entire IP range, trying an ICMP echo, and attempting a connection that "should" either get a response or an ICMP unreachable message when you hit the right IP.

nmap is a useful tool for these kinds of scans. Try first with -sP (ping scan), then with -P0 -sU -p 35-39 whcih means "do not try ping first", "do a UDP scan" and "probe UDP ports

-P0 -sT -p 21,22,25,35-39,80 which is similar but TCP ports 21, 22, 25,