HP FlexFabric 12900 Series Configuration Manual page 185

LLDP frame encapsulated in SNAP
•
Figure 56 SNAP-encapsulated LLDP frame
Table 13 Fields in a SNAP-encapsulated LLDP frame
Field
Destination MAC address
Source MAC address
Type
Data
FCS
LLDPDUs
LLDP uses LLDPDUs to exchange information. An LLDPDU comprises multiple TLVs. Each TLV carries a type
of device information, as shown in
Figure 57 LLDPDU encapsulation format
An LLDPDU can carry up to 32 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
•
LLDP-MED (media endpoint discovery) TLVs
•
Basic management TLVs are essential to device management.
Description
MAC address to which the LLDP frame is advertised. It is the same as that
for Ethernet II-encapsulated LLDP frames.
MAC address of the sending port.
SNAP type for the upper-layer protocol. It is 0xAAAA-0300-0000-88CC
for LLDP.
LLDPDU.
Frame check sequence, a 32-bit CRC value used to determine the validity
of the received Ethernet frame.
Figure 57.
177