Field | Description | |
FCS | Frame check sequence, a | |
the received Ethernet frame. | ||
| ||
|
|
Table 57
b.
3.Fields in a SNAP encapsulated LLDPDU
Field | Description | |
Destination MAC address | The MAC address to which the LLDPDU is advertised. It is fixed to | |
| ||
|
| |
Source MAC address | The MAC address of the sending port. If the port does not have a MAC | |
address, the MAC address of the sending bridge is used. | ||
| ||
|
| |
Type | The | |
| ||
|
| |
Data | LLDPDU. | |
|
| |
FCS | Frame check sequence, a | |
the received Ethernet frame. | ||
| ||
|
|
LLDPDUs
LLDP uses LLDPDUs to exchange information. An LLDPDU comprises multiple TLV sequences. Each carries a specific type of device information, as shown in a.
a.LLDPDU encapsulation format
An LLDPDU can carry up 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.
TLVs
TLVs are type, length, and value sequences that carry information elements. The type field identifies the type of information, the length field indicates the length of the information field in octets, and the value field contains the information itself.
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