CDP Stand for Cisco Discovery Protocol, It's a Layer 2 protocol and used to check the availability of neighbouring Cisco devices. It can give you all the details of the neighbours. CDP provides network device inventory, connectivity information, and IP next hop information. CDP Version-2 (CDPv2) is the most recent release of the protocol and provides more intelligent device tracking features.
Sending CDP packets every 60 seconds and
Hold time is 180 seconds.
Use of SNMP with the CDP Management Information Base (MIB) allows network management applications to learn the device type and the SNMP agent address of neighbouring devices, and to send SNMP queries to those devices. Cisco Discovery Protocol uses the CISCO-CDP-MIB.
To view the neighbours router details, give “show cdp neighbors” command.
Techiebird Router>sh cdp neighbors Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone Device ID Local Intrfce Holdtme Capability Platform Port ID Router Fas 0/1 128 R C1841 Fas 0/1 Router Fas 0/0 128 R C1841 Fas 0/0