LLDP Configuration (Link Layer Discovery Protocol)
- Tracy Yang
LLDP is a standard link-layer discovery protocol which can broadcast its capability, IP address, ID, and interface name as TLVs (Type/Length/Value) in LLDP PDUs (Link Layer Discovery Protocol Data Units).Â
An LLDP PDU includes 4 basic TLVs and several optional TLVs.
Basic TLVs include the Chassis ID, Port ID, TTL and End TLVs.
In L2/L3, you can select the following optional TLVs:
TLV Name | Description |
mac-phy-cfg | MAC address of the system |
management-address | Management IP address of the system |
port-description | The port description of system |
port-vlan | The VLAN ID of the port |
system-capabilities | System capability (e.g. switching, routing) |
system-description | System description |
system-name | System name |
Configuring the LLDP Mode
LLDP supports 4 modes: TxRx, Tx_only, Rx_only, and Disabled. By default, LLDP is disabled.Â
In TxRx mode, the system transmits and receives LLDPDUs. In Tx_only, the system only transmits LLDPDUs. In Rx_only, the system only receives LLDPDUs. In Disabled, the system will not transmit or receive any LLDPDUs.
After enabling LLDP, each interface will be in tx_rx mode by default.
You can configure the system as shown below:
Selecting Optional TLVs
admin@XorPlus# set protocols lldp tlv-select mac-phy-cfg true
admin@XorPlus# set protocols lldp tlv-select management-address true
admin@XorPlus# set protocols lldp tlv-select port-description true
admin@XorPlus# set protocols lldp tlv-select system-capabilities true
admin@XorPlus# commit
Commit OK.
Save done.
admin@XorPlus# Displaying LLDP Information
admin@XorPlus# show protocols lldp
enable: true
> interface "xe-1/1/3" {
> compliance {
> cdp: true
> }
> }
> tlv-select {
> }
admin@XorPlus# run show lldp neighbor all detail
Local Port: te-1/1/1
LLDP info:
---------------------------------------------------------------------------------------
Time To Live: 106
Chassis Id: 68:21:5F:7F:10:C6
Port ID: te-1/1/1
Port Description: te-1/1/1
System Name: PICOS
System Description: Pica8, Inc.,AS5835_54T, PICOS 4.3.2/9b1219e332
System Capability: B, RBridge, Router
System Enabled Capability: Bridge, Router
Management Address: 10.10.51.12
Default VLAN ID: 1
Auto Negotiation: Supported, Enabled
Physical media capabilities: Others, 10base_T, 100base_TX, 100base_TXFD, 1000base_T, 1000base_TFD
Media Attachment Unit type: 1000base_T_Full_Duplex
802.3 Power via MDI :Not available
LLDP MED is not Enabled.
Total entries displayed: 1 Configuring Other Parameters
You can configure other parameters, such as advertisement-interval, hold-time-multiplier, reinit-delay, and transmit-delay, in a similar manner.
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