H3C Technologies H3C S12500 Series Switches - Manual (Page 231)

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Field Description
FCS
Frame check sequence, a 32-bit CRC value used to determine the validity
of the received Ethernet frame.
2. SNAP-encapsulated LLDP frame
Figure 81 SNAP-encapsulated LLDP frame
Table 24 Fields in a SNAP-encapsulated LLDP frame
Field Description
Destination MAC address
MAC address to which the LLDP frame is advertised. It is fixed at
0x0180-C200-000E, a multicast MAC address.
Source MAC address MAC address of the sending port.
Type
SNAP type for the upper layer protocol. This field is
0xAAAA-0300-0000-88CC for LLDP.
Data LLDPDU.
FCS
Frame check sequence, a 32-bit CRC value used to determine the validity
of the received Ethernet frame.
LLDPDUs
LLDP uses LLDPDUs to exchange information. An LLDPDU comprises multiple TLVs. Each TLV carries a type
of device information, as shown in Figure 82 .
Figure 82 LLDPDU encapsulation format
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.
TLVs
A TLV is an information element that contains the type, length, and value fields.
LLDPDU TLVs include the following categories:
• Basic management TLVs
• Organizationally (IEEE 802.1 and IEEE 802.3) specific TLVs