Link Layer Discovery Protocol Commands
This chapter describes the Link Layer Discovery Protocol (LLDP) commands.
lldp debug
Use this command to turn on debugging functions for LLDP.
Use the no form of this command to turn off LLDP debugging functions
Command Syntax
lldp debug (event|rx|tx|message)
no lldp debug (event|rx|tx|message)
Parameters
event
Event debugging
message
NSM message debugging
rx
RX debugging
tx
TX debugging
Command Mode
Exec mode and Privileged Exec mode
Examples
#lldp debug event
#lldp debug messages
lldp ip
Use this command to set the Link Layer Discovery Protocol with an IP address to be used as a chassis and management ID.
Use the no form of this command to remove this value.
Command Syntax
lldp ip address A.B.C.D
no lldp ip address
Parameters
A.B.C.D
Enter the IP address value
Command Mode
Configure mode
Examples
#configure terminal
(config)#lldp ip address 1.1.1.1
(config)#no lldp ip address
lldp run
Use this command to start the Link Layer Discovery Protocol (LLDP).
Use the no form of this command to stop LLDP.
Command Syntax
lldp run
no lldp run
Parameters
None
Command Mode
Configure mode
Example
#configure terminal
(config)#lldp run
(config)#no lldp run
lldp tlv
Use this command to set the TLVs enabled for transmission on a port. Make sure that the complete set of Type Length Values (TLVs) is specified when giving this command, because TLVs not specified are disabled.
Command Syntax
lldp tlv {chassis-id|port-id|ttl|port-description|system-name|system-description|system-capabilities|management-address|ieee-8021-org-specific|ieee-8023-org-specific}
Parameters
chassis-id
Chassis ID type length values (TLV)
port-id
Port ID TLV
ttl
Time to live TLV
port-description
Port description TLV
system-name
System name TLV
system-description
System Description
system-capabilities
System capabilities TLV
management-address
Management address TLV
ieee-8021-org-specific
IEEE 802.1 organizationally-specific TLV
ieee-8023-org-specific
IEEE 802.3 organizationally-specific TLV
Command Mode
Interface mode
Example
#configure terminal
(config)#interface eth0
(config-if)#lldp tlv chassis-id ieee-8021-org-specific ieee-8023-org-specific management-address port-description port-id system-capabilities system-description system-name ttl
lldp tlv-select
Use this command to configure interface LLDP parameters.
This command can be executed globally for all ports (configure mode) or locally for a specific port (interface mode).
When you give this command globally on all ports:
• The show running-config command only displays the options in global mode.
• A global configuration overrides an interface-level configuration. For example, if you disable an option on an interface, it is enabled after enabling the same option globally. If the option was enabled previously, the show output is suppressed and only global mode is displayed (to avoid duplicating the same configuration).
• After enabling a global configuration, when a new LLDP agent is configured on a port, it inherits the global TLV configuration. However, show output does not appear per interface/agent.
• After enabling globally, if you disable an option on an interface, the "no" form for this command is shown for that interface.
• Enabling an already enabled option causes an error.
If you disable globally on all ports:
• The option is removed globally, as well as overrides configurations for all interfaces.
• If the option was not enabled globally, it causes an error.
When enabled locally on a port:
• If the same option was enabled globally, it causes an error.
• If not already enabled, the option is enabled for the given interface alone.
When disabled locally on a port:
• If the option was not present locally or globally, it causes an error.
• If the option was enabled globally, the option is removed from this interface alone. No command will be displayed in show output.
Use the no form of this command to remove interface LLDP parameter configurations.
Command Syntax
lldp tlv-select (port-description|system-name| system-description|system-capabilities|management-address| ieee-8021-org-specific | ieee-8023-org-specific)
no lldp tlv-select (port-description|system-name|system-description|system-capabilities|management-address|ieee-8021-org-specific | ieee-8023-org-specific)
Parameters
port-description
Port description TLV
system-name
System name TLV
system-description
System Description
system-capabilities
System capabilities TLV
management-address
Management address TLV
ieee-8021-org-specific
IEEE 802.1 organizationally-specific TLV
ieee-8023-org-specific
IEEE 802.3 organizationally-specific TLV
Command Mode
Configure mode and interface mode
Example
#configure terminal
(config)#lldp tlv-select system-capabilities
#configure terminal
(config)#interface eth2
(config-if)#lldp-agent
(config-if-lldp-agent)#lldp tlv-select system-capabilities
set lldp chassis-id-tlv
Use this command to set the chassis ID subtype for the LLDP agent on a port.
Command Syntax
set lldp chassis-id-tlv (mac-address | ip-address)
Parameters
mac-address
Use the MAC address as the chassis ID
ip-address
Use the management IP address as the chassis ID
Command Mode
Interface mode
Examples
#configure terminal
(config)#interface eth0
(config-if)#set lldp chassis-id-tlv ip-address
set lldp disable
Use this command to disable the LLDP agent on a port.
Command Syntax
set lldp disable
Parameters
None
Command Mode
Interface mode
Examples
#configure terminal
(config)#interface eth0
(config-if)#set lldp disable
set lldp enable
Use this command to enable an LLDP agent on a port and specify its type.
Command Syntax
set lldp enable (txonly|txrx|rxonly)
Parameters
rxonly
Receive-only
txonly
Transmit-only
txrx
Transmit and receive
Default
By default, no LLDP agent is enabled for a port.
Command Mode
Interface mode
Examples
#configure terminal
(config)#interface eth 0
(config-if)#set lldp enable txrx
set lldp locally-assigned
Use this command to locally set the LLDP port identifier.
Command Syntax
set lldp locally-assigned NAME
Parameters
NAME
Name of the port.
Command Mode
Interface mode
Examples
#configure terminal
(config)#interface eth0
(config-if)#set lldp locally-assigned port1
set lldp management-address-tlv
Use this command to set the management address subtype for the LLDP agent on a port.
Command Syntax
set lldp management-address-tlv (mac-address | ip-address)
Parameters
mac-address
Use the MAC address as the chassis ID
ip-address
Use the management IP address as the chassis ID
Command Mode
Interface mode
Examples
#configure terminal
(config)#interface eth0
(config-if)#set lldp management-address-tlv ip-address
set lldp msg-tx-hold
Use this command to set the Time To Live (TTL) value for LLDPDUs to be transmitted by the port. The value set with this command is multiplied by the
msg-tx-interval value (see
set lldp timer), which determines the final TTL value.
Command Syntax
set lldp msg-tx-hold VALUE
Parameters
VALUE
Time in seconds
Default
The default value of the TTL is 4 seconds.
Command Mode
Interface mode
Examples
#configure terminal
(config)#interface eth0
(config)#set lldp msg-tx-hold 3
set lldp timer
Use this command to set the interval at which LLDP frames are transmitted.
Command Syntax
set lldp timer msg-tx-interval <5-32768>
set lldp timer reinitDelay VALUE
set lldp timer tx-delay <1-8192>
Parameters
<5-32768>
Message transmit interval value
VALUE
Reinit delay value
<1-8192>
Transmit delay value in range of:
(1 <= tx-delay <= ((0.25)* msg-tx-interval)
Default Values
The default value for msg-tx-interval is 30 seconds.
The default value for reinitDelay is 2 seconds.
The default value of the tx-delay is 2 seconds.
Command Mode
Interface mode
Examples
#configure terminal
(config)#interface eth0
(config-if)#set lldp timer msg-tx-interval 40
#configure terminal
(config)#interface eth0
(config-if)#set lldp timer reinitDelay 3
#configure terminal
(config)#interface eth0
(config-if)#set lldp timer tx-delay 3
set lldp too-many-neighbors
Use this command to set the action to take when the remote table is full.
Command Syntax
set lldp too-many-neighbors limit <1-65535> discard received-info timer <1-65535>
set lldp too-many-neighbors limit <1-65535> discard existing-info MAC
timer <1-65535>
Parameters
limit
The limit on the number of LLDP neighbors.
<1-65535>
The limit on the number of LLDP neighbors.
received-info
The information received for this neighbor.
timer
The period after which received information is discarded.
<1-65535>
The period in seconds after which received information is discarded.
existing-info
The information for this neighbor.
MAC
Identifies the remote LLDP Agent for which information is discarded.
timer
The period in seconds after which existing information is discarded.
<1-65535>
The period in seconds after which existing information is discarded.
Default Value
No upper limit is enforced for the number of remote LLDP agents.
Command Mode
Interface mode
Examples
#configure terminal
(config)#interface eth1
(config-if)#set lldp too-many-neighbors limit 20 disc existing-info 1.1.1.1.1 timer 1
(config)#interface eth1
(config-if)#set lldp too-many-neighbors limit 1 discard received-info timer 1
show lldp
Use this command to display LLDP port information.
Command Syntax
show lldp port IFNAME
show lldp port IFNAME statistics
Parameters
IFNAME
Name of the interface
statistics
LLDP port statistics
Command Mode
Exec mode and Privileged Exec mode
Example
The following sample output from this command displays detailed information about an LLDP-enabled port.
#show lldp port eth0
Remote LLDP
MAC Address: 01:06:29:CF:79:A1
TTL: 60
Network Address: 192.168.1.0
Interface Name: eth1
Interface Locally Assigned String: Port-a
Interface Description: bridge
Interface Number: 2
Port Vlan ID: 1
Protocol ID: 274242030202
AutoNego Support: Supported
AutoNego Capability: 1
Operational MAU Type: 3
Link Aggregation Status: Capable
Link Aggregation Port ID: 0
Max Frame Size: 128
System name:
System Description: bridge
System Capabilities: 4
System Capabilities Enabled: 4
The following sample output from this command displays all LLDP statistics for a selected port.
#show lldp port eth0 statistics
LLDP Port statistics for eth0
Frames transmitted: 22
Frames Aged out: 0
Frames Discarded: 0
Frames with Error: 0
Frames Received: 5
TLVs discarded: 0
TLVs unrecognized 0
snmp restart lldp
Use this command to restart SNMP in Link Layer Discovery Protocol (LLDP)
Command Syntax
snmp restart lldp
Parameters
None
Command Mode
Configure mode
Examples
#snmp restart lldp