LLDP Trap
When information in the LLDP local system MIB or the LLDP remote system MIB changes,
the device sends traps to the NMS, requesting the NMS to update the topology. The information
changes include:
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Change of global LLDP status
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Change of local management address
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Change of neighbor information, excluding the change of neighbor management address
The LLDP trap function is applied to all interfaces.
LLDP Packet
shows the LLDP packet format.
Figure 3-2
LLDP packet format
6 octects
DA
SA
LLDP
Ethertype
Data + pad
6 octects
2 octects
1500 octects
4 octects
MAC
address
88-cc
LLDPDU
FCS
LLDP_Multicast
address
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DA: indicates the destination address of the LLDP packet. It is the multicast address 01-80-
C2-00-00-0E.
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SA: indicates the bridge MAC address of the neighbor device.
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LLDP Ethertype: indicates the LLDP packet type. If a packet contains this field, it is an
LLDP packet and it is sent to the LLDP module. The value of this field is 0x88CC.
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LLDPDU: indicates the LLDP data unit. It is the major content of an LLDP packet.
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FCS: indicates the Frame Check Sequence.
LLDPDU in the LLDP packet contains the Layer 2 information discovered by the device, so it
is the most important part in the LLDP packet.
shows the LLDPDU structure.
Figure 3-3
LLDPDU structure
Chassis ID
TLV
M
Port ID
TLV
Time to
Live TLV
Optional
TLV
...
Optional
TLV
End of
LLDPDU
TLV
M
M
C
The basic unit in the LLDPDU is TLV.
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T: information type
Huawei AR150&200 Series Enterprise Routers
Configuration Guide - Network Management
3 LLDP Configuration
Issue 02 (2012-03-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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