You cannot enable or disable LLDP on a Cisco Nexus device. LLDP is enabled on the switch by default. However, the feature lldp command shows as part of the running configuration on the switch, as shown below:
switch# show running-config
!Command: show running-config
!Time: Wed Jan 29 12:36:03 2013
username admin password 5 $1$d8lkfqC8$4VfRuOoZTKvCtTq8VAKbq/ role network-admin
no password strength-check
class-map type qos class-fcoe
class-map type qos match-all c1
The Cisco Discovery Protocol (CDP) is a device discovery protocol that runs over Layer 2 (the data link layer) on all Cisco-manufactured devices (routers, bridges, access servers, and switches). CDP allows network management applications to automatically discover and learn about other Cisco devices connected to the network.
To support non-Cisco devices and to allow for interoperability between other devices, the switch supports the Link Layer Discovery Protocol (LLDP). LLDP is a neighbor discovery protocol that is used for network devices to advertise information about themselves to other devices on the network. This protocol runs over the data-link layer, which allows two systems running different network layer protocols to learn about each other.