Alcatel-Lucent 7750 SR OS - Manual (Page 250)

Configuration Commands
Page 250 7750 SR OS Router Configuration Guide
Priority Policy LAG Events Commands
lag-port-down
Syntax [no] lag-port-down lag-id
Context config>vrrp>policy vrrp-policy-id>priority-event
Description This command creates the context to configure Link Aggregation Group (LAG) priority control
events that monitor the operational state of the links in the LAG.
The lag-port-down command configures a priority control event. The event monitors the operational
state of each port in the specified LAG. When one or more of the ports enter the operational down
state, the event is considered to be set. When all the ports enter the operational up state, the event is
considered to be clear. As ports enter the operational up state, any previous set threshold that
represents more down ports is considered cleared, while the event is considered to be set.
Multiple unique lag-port-down event nodes can be configured within the priority-event node up to
the maximum of 32 events.
The lag-port-down command can reference an arbitrary LAG. The lag-id does have to already exist
within the system. The operational state of the lag-port-down event will indicate:
• Set – non-existent
• Set – one port down
• Set – two ports down
• Set – three ports down
• Set – four ports down
• Set – five ports down
• Set – six ports down
• Set – seven ports down
• Set – eight ports down
• Cleared – all ports up
When the lag-id is created, or a port in lag-id becomes operationally up or down, the event
operational state must be updated appropriately.
When one or more of the LAG composite ports enters the operationally down state or the lag-id is
deleted or does not exist, the event is considered to be set. When an event transitions from clear to
set, the set is processed immediately and must be reflected in the associated virtual router instances
in-use priority value. As the event transitions from clear to set, a hold set timer is loaded with the
value configured by the events hold-set command. This timer prevents the event from clearing until
it expires, damping the effect of event flapping. If the event clears and becomes set again before the
hold set timer expires, the timer is reset to the hold-set value, extending the time before another clear
can take effect.
The lag-port-down event is considered to have a tiered event set state. While the priority impact per
number of ports down is totally configurable, as more ports go down, the effect on the associated
virtual router instances in-use priority is expected to increase (lowering the priority). When each