Comparison Between CDP and LLDP in Cisco ACI

 Comparison Between CDP and LLDP in Cisco ACI 

Note :- Both CDP and LLDP can be enabled at the same time.

Feature	CDP (Cisco Discovery Protocol)	LLDP (Link Layer Discovery Protocol)
Vendor Support	Cisco proprietary	Vendor-neutral (IEEE 802.1ab standard)
Protocol Layer	Data Link Layer	Data Link Layer
Device Discovery Scope	Cisco devices only	Cisco and non-Cisco devices
Communication Type	Periodic advertisements (multicast)	One-way advertisements
Information Shared	Protocol addresses, platform, SNMP address, hold-time	Device capabilities, identity, configuration via TLVs
TLV Support	Limited to Cisco-defined TLVs	Standardized TLVs (Type-Length-Value)
Max Neighbors per Port	Up to 256	One device per port
ACI Support (from Release 4.2(1))	Supported on leaf/spine management interfaces	Supported on leaf/spine management interfaces
ACI Configuration Scope	Can be enabled globally across fabric	Can be enabled globally across fabric
ACI Use Case	Troubleshooting cabling issues, especially in unstaffed sites	Same as CDP
ACI Interface Support	Physical interfaces and port channels only	Same, but not supported on FEX interfaces
ACI VLAN TLV Limitations	Not applicable	Only 25 VLANs advertised; name TLV limited to 32 characters
ACI Infra-VLAN Advertisement	Not specified	Not advertised even if enabled
ACI Routed Sub-interface VLANs	Not specified	Not advertised
Default Behavior on Fabric Ports	Not supported between fabric-connected interfaces	Enabled by default on fabric ports