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show lldp

 

Syntax

Release Information

Command introduced in Junos OS Release 9.0 for EX Series switches.

Command introduced in Junos OS Release 11.1 for the QFX Series.

Command introduced in Junos OS Release 14.1X53-D20 for OCX Series switches.

Description

Display information about Link Layer Discovery Protocol (LLDP) and Link Level Discovery Protocol–Media Endpoint Discovery (LLDP-MED) configuration and capabilities on the switch. LLDP and LLDP-MED are used to learn about and to distribute device information on network links.

Options

noneDisplay LLDP information for all interfaces.
detail(Optional) Display detailed LLDP information for all interfaces.

Required Privilege Level

view

List of Sample Output

show lldp (EX3200 switches)

show lldp (EX4300 switches)

show lldp detail (EX4300 switches)

show lldp detail (EX3400 switches with VLAN name TLV)

Output Fields

Table 1 lists the output fields for the show lldp command. Output fields are listed in the approximate order in which they appear.

Table 1: show lldp Output Fields

Field Name

Field Description

Level of Output

LLDP

LLDP operating state. The state can be enabled or disabled.

Note: If a VLAN that has been configured for untagged packets on an interface also has Layer 2 protocol tunneling (L2PT) enabled for LLDP, the LLDP operating state for that interface is displayed as disabled.

All levels

Advertisement interval

Frequency, in seconds, at which LLDP advertisements are sent.

This value is set by the advertisement-interval configuration statement.

All levels

Transmit delay

Seconds of delay before advertisements are sent to neighbors following a change to a TLV (type, length, or value) element in the LLDP protocol or to the state of the local system, such as a change in hostname or management address. You can set this value to reduce the delay in notifying neighbors of a change in the local system.

This value is set by the transmit-delay configuration statement.

All levels

Hold timer

On EX4300 switches, the hold timer shows the length of time LLDP information is held before it is discarded. The hold timer value is equal to the advertisement interval multiplied by the hold multiplier.

On all other switches, the hold timer shows the value of the hold multiplier.

The hold multipler value is set by the hold-multiplier configuration statement.

All levels

Notification interval

How often LLDP trap notifications are generated as a result of LLDP database changes. If the interval value is 0, LLDP trap notifications on database changes are disabled.

This value is set by the lldp-configuration-notification-interval configuration statement.

All levels

Config Trap Interval

How often LLDP trap notifications are generated as a result of changes in topology—for example, when an endpoint connects or disconnects. If the interval value is 0, LLDP trap notifications on topology changes are disabled.

This value is set by the ptopo-configuration-trap-interval configuration statement.

All levels

Connection Hold timer

Amount of time the system maintains dynamic topology entries.

This value is set by the ptopo-configuration-maximum-hold-time configuration statement.

All levels

LLDP-MED

LLDP-MED operating state. The state can be Enabled or Disabled.

All levels

MED fast start count

Number of advertisements sent from a switch to a device, such as a VoIP telephone, when the device is first detected by the switch. These increased advertisements are temporary. After a device and a switch exchange information and can communicate, advertisements are reduced to one per second.

This value is set by using the fast-start configuration statement.

All levels

Interface

Name of the interface for which LLDP configuration information is being reported.

All levels

Parent Interface

Name of the aggregated Ethernet interface, if any, to which the interface belongs.

All levels

LLDP

LLDP operating state. The state can be Enabled or Disabled.

All levels

Power Negotiation

LLDP power negotiation operating state. The state can be Enabled or Disabled.

All levels

Neighbor count

Total number of new LLDP neighbors detected since the last switch reboot.

detail

Interface

Name of the interface that is advertising VLAN information.

All levels

Vlan-id

VLAN tag associated with the interface sending LLDP frames. If the interface is not a member of a VLAN, the VLAN ID is advertised as 0.

detail

Vlan-name

VLAN name associated with the VLAN ID.

For switches running Junos OS releases with Enhanced Layer 2 Software (ELS), this column displays the string vlan-vlan-id by default. Starting in Junos OS Release 15.1X53-D59 and 18.2R1, you can configure the vlan-name-tlv-option name option at the [edit protocols lldp] hierarchy level to transmit the VLAN name in the LLDP VLAN name TLV in place of the VLAN ID, and display the actual VLAN name in this output field instead.

detail

LLDP basic TLVs supported

Basic TLVs supported on the switch:

  • Chassis identifier—TLV that advertises the MAC address associated with the local system.

  • Port identifier—TLV that advertises the port identification for the specified port in the local system.

  • Port description—Interface name for the port.

  • System name—TLV that advertises the user-configured name of the local system.

  • System description—TLV that advertises the system description containing information about the software and current image running on the system. This information is taken from the software and is not configurable.

  • System capabilities—TLV that advertises the primary functions performed by the system—for example, bridge or router.

  • Management address—TLV that advertises the IP management address of the local system.

detail

Supported LLDP 802 TLVs

802.3 TLVs supported on the switch:

  • MAC/PHY configuration status—TLV that advertises information about the physical interface, such as autonegotiation status and support and MAU type. The information is based on the physical interface structure and is not configurable.

  • Power via MDI—TLV that advertises MDI power support, PSE power pair, and power class information.

  • Link aggregation—TLV that advertises if the interface is aggregated and its aggregated interface ID.

  • Maximum frame size—TLV that advertises the maximum transmission unit (MTU) of the interface sending LLDP frames.

  • Port VLAN tag—TLV that advertises the VLAN tag configured on the interface.

  • Port VLAN name—TLV that advertises the VLAN name configured on the interface.

detail

Supported LLDP MED TLVs

LLDP-MED TLVs supported on the switch:

  • LLDP MED capabilities—TLV that advertises the primary function of the port. The capabilities values range from 0 through 15:

    • 0—Capabilities

    • 1—Network Policy

    • 2—Location Identification

    • 3—Extended Power via MDI-PSE

    • 4—Inventory

    • 5–15—Reserved

  • Network policy—TLV that advertises the port VLAN configuration and associated Layer 2 and Layer 3 attributes. Attributes include the policy identifier, application types—such as voice or streaming video—802.1Q VLAN tagging, and 802.1p priority bits and DiffServ code points.

  • Endpoint location—TLV that advertises the physical location of the endpoint.

  • Extended power Via MDI—TLV that advertises the power type, power source, power priority, and power value of the port. It is the responsibility of the PSE device (network connectivity device) to advertise the power priority on a port.

detail

Sample Output

show lldp (EX3200 switches)

user@switch> show lldp

show lldp (EX4300 switches)

user@switch> show lldp

show lldp detail (EX4300 switches)

user@switch> show lldp detail

show lldp detail (EX3400 switches with VLAN name TLV)

user@switch> show lldp detail