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overwhelming the network during times of frequent changes to local device information, an interval is
introduced between two successive LLDPDUs.
This interval is shortened to 1 second in either of the following cases:
A new neighbor is discovered, in other words, a new LLDPDU 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.
This is the fast sending mechanism of LLDP. With this mechanism, a specific number of LLDPDUs are sent
successively at 1-second intervals, to help LLDP neighbors discover the local device as soon as possible.
Then, the normal LLDPDU transmit interval resumes.
Receiving LLDPDUs
An LLDP-enabled port that is operating in TxRx mode or Rx mode checks the validity of TLVs carried in
every received LLDPDU. If valid, the information is saved and an aging timer is set for it based on the
time to live (TTL) value in the Time To Live TLV carried in the LLDPDU. If the TTL value is 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
LLDP configuration task list
Complete these tasks to configure LLDP:
Performing basic LLDP
configuration
Setting the LLDP operating mode
Setting the LLDP re-initialization delay
Configuring the advertisable TLVs
Configuring the management address and its
encoding format
Setting other LLDP parameters
Setting an encapsulation format for LLDPDUs
Configuring CDP compatibility
Configuring LLDP trapping
NOTE:
LLDP-related configurations made in Ethernet interface view take effect only on the current port, and
those made in port group view take effect on all ports in the current port group.
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