Manual Chapter : Implementing the Link Layer Discovery Protocol

Applies To:

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  • 11.5.0

BIG-IP Analytics

  • 11.5.0


  • 11.5.0


  • 11.5.0


  • 11.5.0

BIG-IP Link Controller

  • 11.5.0


  • 11.5.0


  • 11.5.0


  • 11.5.0
Manual Chapter

Overview: Implementing Link Layer Discovery Protocol

The BIG-IP system supports Link Layer Discovery Protocol (LLDP). LLDP is a Layer 2 industry-standard protocol (IEEE 802.1AB) that gives a network device such as the BIG-IP system the ability to advertise its identity and capabilities to multi-vendor neighbor devices on a network. The protocol also enables a network device to receive information from neighbor devices.

LLDP transmits device information in the form of LLDP messages known as LLDP Packet Data Units (LLDPDUs).

In general, this protocol:

  • Advertises connectivity and management information about the local BIG-IP device to neighbor devices on the same IEEE 802 LAN.
  • Receives network management information from neighbor devices on the same IEEE 802 LAN.
  • Operates with all IEEE 802 access protocols and network media.

Using the BIG-IP Configuration utility or tmsh, you can use this particular implementation to configure BIG-IP system interfaces to transmit LLDPDUs to neighbor devices. More specifically, you can:

  • Specify the exact content of LLDPDUs that a BIG-IP system interface transmits to a neighbor device. You specify this content by configuring the LLDP Attributes setting on each individual interface.
  • Globally specify the frequencies of various message transmittal properties, and specify the number of neighbors from which interfaces can receive messages. These properties apply to all interfaces on the BIG-IP system.

The following illustration shows a BIG-IP system that transmits LLDP messages to three neighbor devices: another BIG-IP system, an external switch, and an external router. Note that LLDP is enabled on all of the devices.

BIG-IP system and LLDP transmittal The BIG-IP system and LLDP transmittal

Task summary

Perform these tasks to implement Link Layer Discovery Protocol (LLDP) on selected BIG-IP system interfaces.

Task list

Configuring global LLDP properties

You can configure a set of general LLDP properties that apply to all interfaces on the BIG-IP system. These settings pertain to LLDP message transmission frequencies and the maximum number of neighbors to which each interface can send LLDP messages.

Note: Although you use this procedure to globally enable the LLDP feature on the BIG-IP system, you can also disable LLDP for any individual interface. You do this by configuring the specific properties of that interface.
  1. On the Main tab, click Network > Interfaces > LLDP > General. This displays the general LLDP properties that you can configure on the system.
  2. From the LLDP list, select Enabled.
  3. For the remainder of the settings, retain or change the default values.
  4. Click Update.
This task activates support for the LLDP protocol on the BIG-IP system, and configures the system to transmit LLDPDUs according to the specified frequencies.

Configuring LLDP settings for an individual interface

You can use this procedure to configure the settings for an individual interface on the BIG-IP system.
  1. On the Main tab, click Network > Interfaces > Interface List. The Interface List screen displays the list of interfaces on the system.
  2. In the Name column, click an interface number. This displays the properties of the interface.
  3. For the State setting, verify that the interface is set to Enabled.
  4. For the LLDP setting, verify that the property is set to Transmit Only.
  5. For the LLDP Attributes setting, verify that the list of attributes in the Send field includes all Time Length Values (TLVs) that you want the BIG-IP system interface to send to neighbor devices.
  6. Click Update.
After you perform this task, the interface is configured to send the specified LLDP information to neighbor devices.

Implementation result

This implementation results in this LLDP configuration:

  • Support for the LLDP protocol is enabled on the BIG-IP system.
  • For all BIG-IP system interfaces, the BIG-IP system attempts to transmit LLDPDUs to neighbor devices every 30 seconds, with a minimum delay between transmissions of 2 seconds.
  • The maximum number of neighbors to which each BIG-IP system interface can send LLDPDUs is 10.
  • Every BIG-IP system interface can send LLDPDUs to its neighbors.
  • No BIG-IP system interface can receive LLDPDUs from its neighbors.

In addition, the content of the LLDPDUs that each BIG-IP system interface sends to its neighbors contains this information:

  • Chassis ID
  • Port ID
  • Time-to-Live value
  • Port description
  • System name
  • System description
  • System capabilities
  • Port VLAN ID
  • Port and protocol VLAN ID
  • VLAN name
  • Protocol identity
  • MAC/PHY config status
  • Link aggregation
  • Max frame size
  • Product model