Working Mechanism; Protocols And Standards - HP 3100 Series Configuration Manual

Type
Asset ID
Location Identification
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 a port changes, its LLDP protocol state machine reinitializes.
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,
an interval is introduced between two successive LLDP frames.
This interval is shortened to 1 second in either of the following cases:
•
A new LLDP frame is received and carries device information new to the local device.
•
The LLDP operating mode of the port changes from Disable or Rx to TxRx or Tx.
The fast LLDP frame transmission mechanism successively sends the specified number of LLDP
frames at 1-second interval. This 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 LLDP agent saves the information and starts
an aging timer. When the TTL value in the Time To Live TLV carried in the LLDP frame becomes zero,
the information ages out immediately.

Protocols and standards

•
IEEE 802.1AB-2005, Station and Media Access Control Connectivity Discovery
•
ANSI/TIA-1057, Link Layer Discovery Protocol for Media Endpoint Devices
Description
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.
Allows a network device to advertise the appropriate location
identifier information for a terminal device to use in the context of
location-based applications.
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