'show arp' not showing hosts in 2960x stack

[Gonzo1]

Hello,

On our DHCP server I can see a device that is plugged into VLAN 70 that is non corporate device as it says it's an android device.

I've gone onto our Cisco 2960x stack and ran the 'show arp' command and it only show the management IPs.

The Cisco stack connects for a port channel to a Nexus core switch and a 'show arp' will show the IPs, but not the port.

Any ideas why the stack doesn't hold this info?

Thanks

[Giuseppe Larosa]

Hello,

the C2960X is working as a L2 LAN switch

if you know the MAC address of this device from the show ip arp on the core switch

do on the access layer switch the following:

show mac address-table address aabb.ccdd.eefff

to find to which port is connected.

But if it is an Android my guess is this is a WIFI client so its MAC address will be seen on the WLC port.

Have you got a wireless controller connected to the C2960x switch?

In any case the show mac ... will tell you where the MAC address is learned.

Hope to help

Giuseppe