Configuring for Network Management Applications

LLDP (Link-Layer Discovery Protocol)

Syntax setmib lldpTxDelay.0 -i < 1 - 8192 >

Uses setmib to change the minimum time (delay-interval) any LLDP port will delay advertising successive LLDP advertisements due to a change in LLDP MIB content. (Default: 2; Range: 1 - 8192)

Note: The LLDP refresh-interval (transmit interval) must be greater than or equal to (4 x delay-interval). The switch does not allow increasing the delay interval to a value that conflicts with this relationship. That is, the switch displays Inconsistent value if (4 x delay-interval) exceeds the current transmit interval, and the command fails. Depending on the current refresh-interval setting, it may be necessary to increase the refresh-interval before using this command to increase the delay-interval.

For example, to change the delay-interval from 2 seconds to 8 seconds when the refresh-interval is at the default 30 seconds, you must first set the refresh- interval to a minimum of 32 seconds (32 = 4 x 8).

Attempt to change the transmit-delay interval shows that the refresh- interval is less than (4 x delay-interval).

Successfully changes the transmit-

 

Changes the refresh-interval to 32; that is:

delay interval to 8.

 

32 = 4 x (desired transmit-delay interval)

 

 

 

Figure 13-15. Example of Changing the Transmit-Delay Interval

Changing the Reinitialization Delay Interval. In the default configuration, a port receiving a disable command followed immediately by a txonly, rxonly, or tx_rx command delays reinitializing for two seconds, during which time LLDP operation remains disabled. If an active port is subjected to frequent toggling between the LLDP disabled and enabled states, LLDP advertisements are more frequently transmitted to the neighbor device. Also, the neighbor table in the adjacent device will change more frequently, as it deletes, then replaces LLDP data for the affected port which, in turn, generates SNMP traps (if trap receivers and SNMP notification are configured). All of this can unnecessarily increase network traffic. Extending the reinitialization-

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