H3C Technologies H3C S5560 Series Switches - Manual (Page 268)

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Figure 71 LLDP neighbor relationships
LLDP frame formats
LLDP sends device information in LLDP frames. LLDP frames are encapsulated in Ethernet II or SNAP
frames.
• LLDP frame encapsulated in Ethernet II
Figure 72 Ethernet II-encapsulated LLDP frame
Table 19 Fields in an Ethernet II-encapsulated LLDP frame
Field Description
Destination MAC address
MAC address to which the LLDP frame is advertised. LLDP specifies
different multicast MAC addresses as destination MAC addresses for LLDP
frames destined for agents of different types. This helps distinguish
between LLDP frames sent and received by different agent types on the
same interface. The destination MAC address is fixed to one of the
following multicast MAC addresses:
• 0x0180-C200-000E for LLDP frames destined for nearest bridge
agents.
• 0x0180-C200-0000 for LLDP frames destined for nearest customer
bridge agents.
• 0x0180-C200-0003 for LLDP frames destined for nearest non-TPMR
bridge agents.
Source MAC address MAC address of the sending port.
Type Ethernet type for the upper-layer protocol. It is 0x88CC for LLDP.
Data LLDPDU. An LLDP frame contains only one LLDPDU.
FCS
Frame check sequence, a 32-bit CRC value used to determine the validity
of the received Ethernet frame.
GE1/0/2 GE1/0/3
CB 1 SB 1 CB 2
GE1/0/4 GE1/0/1
Nearest
customer
bridge
Nearest
customer
bridge
Nearest non-
TPMR bridge
Nearest bridge
Nearest non-
TPMR bridge
Nearest bridge
Nearest non-
TPMR bridge
Nearest bridge
Nearest non-
TPMR bridge
Nearest bridge