Description: Enables/disables CDP awareness for the interface.

CDP is Cisco's equivalent to LLDP.

The CDP operation is restricted to decoding incoming CDP frames (The switch doesn't transmit CDP frames). CDP frames are only decoded if LLDP on the port is enabled.

Only CDP TLVs that can be mapped to a corresponding field in the LLDP neighbors' table are decoded. All other TLVs are discarded (Unrecognized CDP TLVs and discarded CDP frames are not shown in the LLDP statistics.).

CDP TLVs are mapped onto LLDP neighbors' table as shown below.

CDP TLV 'Device ID' is mapped to the LLDP 'Chassis ID' field.

CDP TLV 'Address' is mapped to the LLDP 'Management Address' field. The CDP address TLV can contain multiple addresses, but only the first address is shown in the LLDP neighbors table.

CDP TLV 'Port ID' is mapped to the LLDP 'Port ID' field.

CDP TLV 'Version and Platform' is mapped to the LLDP 'System Description' field.

Both the CDP and LLDP support 'system capabilities', but the CDP capabilities cover capabilities that are not part of the LLDP. These capabilities are shown as 'others' in the LLDP neighbors' table.

If all ports have CDP awareness disabled the switch forwards CDP frames received from neighbor devices. If at least one port has CDP awareness enabled all CDP frames are terminated by the switch.

Note: When CDP awareness on a port is disabled the CDP information isn't removed immediately, but gets removed when the hold time is exceeded.