This document provides a sample configuration and verification for the
Link Layer Discovery Protocol (LLDP) features on the Catalyst
3750/3750-E/3750-X Series Switches. Specifically, this document shows you how
to configure the port-based traffic control features on a Catalyst 3750
Make sure that you meet these requirements before you attempt this
Have basic knowledge of configuration on Cisco Catalyst
3750/3750-E/3750-X Series Switches
Have basic understanding of LLDP features
The information in this document is based on Cisco Catalyst 3750 Series
The information in this document was created from the devices in a
specific lab environment. All of the devices used in this document started with
a cleared (default) configuration. If your network is live, make sure that you
understand the potential impact of any command.
LLDP is a neighbor discovery protocol that allows non-Cisco devices to
advertise information about themselves to other devices on the network. Cisco
switches supports the IEEE 802.1AB LLDP which allow non-Cisco devices for
interoperability between other devices. LLDP runs over the data-link layer
which allows two devices running different network layer protocols to learn
about each other.
LLDP discovers neighbor devices by using a set of attributes that
contain type, length, and value descriptions. These attributes are referred to
as TLVs. LLDP supported devices can use TLVs to receive and send information to
their neighbors. This protocol can advertise details such as configuration
information, device capabilities, and device identity.
The switch supports these basic management TLVs, which are mandatory
Port description TLV
System name TLV
System description TLV
System capabilities TLV
Management address TLV
These organizationally-specific LLDP TLVs are also advertised to
Port VLAN ID TLV (IEEE 802.1 organizationally specific
!--- Enable LLDP globally on the switch.
!--- Specify time for the device to hold LLDP information.
Switch(config)#lldp holdtime 180
!--- Set the time for sending frequency of LLDP updates.
Switch(config)#lldp timer 50
!--- Enable LLDP specific to an interface.
Switch(config)#interface gigabitethernet 1/0/1
!--- Enable the interface to send LLDP.
!--- Enable the interface to receive LLDP.
!--- Return to privileged EXEC mode.
!--- Save the configurations in the device.
switch(config)#copy running-config startup-config
!--- Disable LLDP feature on the switch.
Switch(config)#no lldp run
Use this section to confirm that your configuration works
Switch#show lldp neig detail
Chassis id: 126.96.36.199
Port id: 0019.e1e7.018d
Port Description: Nortel IP Phone
System Name - not advertised
Nortel IP Telephone 1230E, Firmware:062AC53
Time remaining: 166 seconds
System Capabilities: B,T
Enabled Capabilities: T
Management Addresses - not advertised
Auto Negotiation - supported, enabled
Physical media capabilities:
Symm, Asym Pause(FD)
Media Attachment Unit type: 16
(NP) Network Policy, (LI) Location Identification
(PS) Power Source Entity, (PD) Power Device
F/W revision: 062AC53
Model: IP Phone 1230E
Capabilities: NP, LI, PD, IN
Device type: Endpoint Class III
Network Policy(Voice): Unknown
PD device, Power source: Unknown, Power Priority: High, Wattage: 6.0
Switch#show lldp traffic
LLDP traffic statistics:
Total frames out: 560
Total entries aged: 0
Total frames in: 211
Total frames received in error: 0
Total frames discarded: 0
Total TLVs discarded: 208
Total TLVs unrecognized: 208