Alcatel-Lucent 7750 SR-OS, Configuration Manual

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VRRP
7750 SR OS Router Configuration Guide Page 317
Port Down Priority Event
The port down priority event is tied to either a physical port or a SONET/SDH channel. The port or
channel operational state is evaluated to determine a port down priority event or event clear.
When the port or channel operational state is up, the port down priority event is considered false or
cleared. When the port or channel operational state is down, the port down priority event is
considered true or set.
LAG Degrade Priority Event
The LAG degrade priority event is tied to an existing Link Aggregation Group (LAG). The LAG
degrade priority event is conditional to percentage of available port bandwidth on the LAG.
Multiple bandwidth percentage thresholds may be defined, each with its own priority value.
If the LAG transitions from one threshold to the next, the previous threshold priority value is
subtracted from the total delta sum while the new threshold priority value is added to the sum. The
new sum is then subtracted from the base priority and compared to the delta in-use priority limit to
derive the new in-use priority on the virtual router instance.
The following example illustrates a LAG priority event and it’s interaction with the hold set timer
in changing the in-use priority.
The following state and timer settings are used for the LAG events displayed in Table 6 :
• User-defined thresholds: 2 ports down 4 ports down 6 ports down
• LAG configured ports: 8 ports
• Hold set timer (hold-set): 5 seconds
Table 6: LAG Events
Time LAG Port State Parameter State Comments
0 All ports down Event State Set - 8 ports down
Event Threshold 6 ports down
Hold Set Timer 5 seconds Set to hold-set parameter