Configuring LLDP Timers

The LLDP timers apply to the entire switch and are not configurable by port. After you enable LLDP, LLDP timers control the time periods for the transmission and storage of LLDP TLVs as follows:
  • Reinitialization period (default is two seconds).

  • Delay between LLDP transmissions (default is two seconds)—applies to triggered updates, or updates that are initiated by a change in the topology.

  • Transmit interval (default is 30 seconds)—applies to messages sent periodically as part of protocol.

  • Time-to-live (TTL) value (default is two minutes)—time that the information remains in the recipient‘s LLDP database.


    Once the LLDP MED TLVs begin transmitting (after detecting LLDP MED TLVs from a connected endpoint), those TLVs are also controlled by these timers.

When LLDP is disabled or if the link goes down, LLDP is reinitialized. The reinitialize delay is the number of seconds the port waits to restart the LLDP state machine; the default is two seconds.

The time between triggered update LLDP messages is referred to as the transmit delay, and the default value is two seconds. You can change the default transmit delay value to a specified number of seconds or to be automatically calculated by multiplying the transmit interval by 0.25.

Each LLDP message contains a TTL value. The receiving LLDP agent discards all LLDP messages that surpass the TTL value; the default value is 120 seconds. The TTL is calculated by multiplying the transmit interval value and the transmit hold value; the default transmit hold value is four.