9 lldp, 1 management lldp, 1 configuration – Signamax Managed Hardened PoE Industrial DIN-rail Mount Switch User Manual
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9 LLDP
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9 LLDP
Note: Enable LLDP in
In a heterogeneous network, it is important that different types of network devices from
different vendors can discover one another and exchange configuration for interoperability and
management sake. Therefore, a standard configuration exchange platform was created.
The IETF drafted the Link Layer Discovery Protocol (LLDP) in IEEE 802.1AB. The protocol
operates on the data link layer to exchange device information between directly connected
devices. With LLDP, a device sends local device information (including its major functions,
management IP address, device ID, and port ID) as TLV (type, length, and value) triplets in
Link Layer Discovery Protocol Data Units (LLDPDUs) to the directly connected devices, and at
the same time, stores the device information received in LLDPDUs sent from the LLDP
neighbors in a standard management information base (MIB). It allows a network management
system to fast detect Layer-2 network topology change and identify what the change is.
9.1 Management LLDP
9.1.1 Configuration
This page configures LLDP for a specified Ethernet port.
Configuration Steps:
Step 1
Specify the port to configure LLDP;
Step 2
Enable or disable LLDP on the port;
Step 3
Specify the LLDP status: Disabled, Tx and Rx, Tx Only and Rx Only;
Step 4
Specify the encapsulation format: Ethernet II and SNAP.
LLDP uses LLDPDUs to exchange information. An LLDPDU comprises multiple type, length,
and value (TLV) sequences. Each carries a specific type of device information, as shown in
the flowing LLDPDU encapsulation format figure.
An LLDPDU can carry up to 28 types of TLVs. Mandatory TLVs include Chassis ID TLV, Port
ID TLV, Time To Live TLV, and End of LLDPDU TLV. Other TLVs are optional.
LLDP sends device information in LLDP data units (LLDPDUs). LLDPDUs are encapsulated in
Ethernet II or SubNetwork Access Protocol (SNAP) frames.
(1) Ethernet II-encapsulated LLDPDU format