Using show CDP neighbors detail you will get this info:
Device ID:
Entry address(es):
IP address:
Platform:
Capabilities:
Interface:
Port ID (outgoing port):
Holdtime :
Version :
advertisement version:
Protocol Hello:
VTP Management Domain:
Duplex:
Management address(es):
Device ID:
Entry address(es):
IP address:
Platform:
Capabilities:
Interface:
Port ID (outgoing port):
Holdtime :
Version :
advertisement version:
Protocol Hello:
VTP Management Domain:
Duplex:
Management address(es):
BUT IP is not a good identifier because it could be modified manually, I would prefer to use show version or show inventory to get the serial number of the device.