Dell(conf)#interface Gigabitethernet 4/16Dell(conf-if-gi-4/16)#no shutdownDell(conf-if-gi-4/16)#port-channel-protocol lacpDell(conf-if-gi-4/16-lacp)#port-channel 32 mode activeThe port-channel 32 mode active command shown here may be successfully issued as long as there is no existing static channel-member configuration in LAG 32.Setting the LACP Long TimeoutPDUs are exchanged between port channel (LAG) interfaces to maintain LACP sessions.PDUs are transmitted at either a slow or fast transmission rate, depending upon the LACP timeout value. The timeout value is theamount of time that a LAG interface waits for a PDU from the remote system before bringing the LACP session down. The defaulttimeout value is 1 second. You can configure the default timeout value to be 30 seconds. Invoking the longer timeout might preventthe LAG from flapping if the remote system is up but temporarily unable to transmit PDUs due to a system interruption.NOTE: The 30-second timeout is available for dynamic LAG interfaces only. You can enter the lacp long-timeoutcommand for static LAGs, but it has no effect.To configure LACP long timeout, use the following command.• Set the LACP timeout value to 30 seconds.CONFIG-INT-PO modelacp long-timeoutExample of the lacp long-timeout and show lacp CommandsDell(conf)# interface port-channel 32Dell(conf-if-po-32)#no shutdownDell(conf-if-po-32)#switchportDell(conf-if-po-32)#lacp long-timeoutDell(conf-if-po-32)#endDell# show lacp 32Port-channel 32 admin up, oper up, mode lacpActor System ID: Priority 32768, Address 0001.e800.a12bPartner System ID: Priority 32768, Address 0001.e801.45a5Actor Admin Key 1, Oper Key 1, Partner Oper Key 1LACP LAG 1 is an aggregatable linkA - Active LACP, B - Passive LACP, C - Short Timeout, D - Long TimeoutE - Aggregatable Link, F - Individual Link, G - IN_SYNC, H - OUT_OF_SYNCI - Collection enabled, J - Collection disabled, K - Distribution enabled L -Distribution disabled,M - Partner Defaulted, N - Partner Non-defaulted, O - Receiver is in expiredstate,P - Receiver is not in expired statePort Te 3/6 is enabled, LACP is enabled and mode is lacpActor Admin: State ADEHJLMP Key 1 Priority 128To view the PDU exchanges and the timeout value, use the debug lacp command. For more information, refer to Monitoring andDebugging LACP.Monitoring and Debugging LACPThe system log (syslog) records faulty LACP actions.To debug LACP, use the following command.• Debug LACP, including configuration and events.EXEC mode[no] debug lacp [config | events | pdu [in | out | [interface [in | out]]]]378 Link Aggregation Control Protocol (LACP)
