H3C Technologies H3C S12500 Series Switches - Manual (Page 234)

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Type Description
Manufacturer Name Allows a terminal device to advertise its vendor name.
Model Name Allows a terminal device to advertise its model name.
Asset ID
Allows a terminal device to advertise its asset ID. The typical case
is that the user specifies the asset ID for the endpoint to facilitate
directory management and asset tracking.
Location Identification
Allows a network device to advertise the appropriate location
identifier information for a terminal device to use in the context of
location-based applications.
Management address
The network management system uses the management address of a device to identify and manage the
device for topology maintenance and network management. The management address is encapsulated
in the management address TLV.
Working mechanism
LLDP operating modes
LLDP can operate in one of the following modes:
• TxRx mode—A port in this mode can send and receive LLDP frames.
• Tx mode—A port in this mode can only send LLDP frames.
• Rx mode—A port in this mode can only receive LLDP frames.
• Disable mode—A port in this mode cannot send or receive LLDP frames.
Each time the LLDP operating mode of an LLDP agent changes, its LLDP protocol state machine
re-initializes. A configurable reinitialization delay prevents frequent initializations caused by frequent
changes to the operating mode. If you configure the reinitialization delay, an LLDP agent must wait the
specified amount of time to initialize LLDP after the LLDP operating mode changes.
Transmitting LLDP frames
An LLDP-enabled port operating in TxRx mode or Tx mode sends LLDP frames to its directly connected
devices both periodically and when the local configuration changes. To prevent LLDP frames from
overwhelming the network during times of frequent changes to local device information, LLDP adds a
frame transmission interval between two successive LLDP frames.
This interval is shortened to 1 second in either of the following cases:
• A new neighbor is discovered. A new LLDP frame is received carrying device information new to the
local device.
• The LLDP operating mode of the port changes from Disable/Rx to TxRx or Tx.
The fast LLDP frame transmission mechanism successively sends the specified number of LLDP frames at
a 1-second interval. The mechanism helps LLDP neighbors discover the local device as soon as possible.
Then, the normal LLDP frame transmission interval resumes.
Receiving LLDP frames
An LLDP-enabled port operating in TxRx mode or Rx mode confirms the validity of TLVs carried in every
received LLDP frame. If the TLVs are valid, the information is saved and an aging timer is set for it based