HP UX Auto Port Aggregation (APA) Software manual Assign a priority to the aggregates

2.Assign a priority to the aggregates.

If you prefer lan900 to be the active port when both link aggregates have the same number of operational ports, assign lan900 a higher priority. If you do not, the active port changes when one of the link aggregates becomes more efficient (has more operational ports or higher bandwidth). In this example, you assign lan900 a priority of 5 and lan901 a priority of 3.

3.Edit the lanconfig.ascii configuration file.

FAILOVER_GROUPlan902

	STATIONARY_IP	192.19.20.2
#	Primary/Standby	Interface			Priority : Cost
#	–––––––––––––––––––––––+–––––––––––––+––––––––––––––––
	PRIMARY	lan900	5	: 1
	STANDBY	lan901	3	: 1

Table C-1lists lan900 events for this example and how proactive failover determines the active port for lan902.

Table C-1 lan900 Events and Proactive Failover (Equal Network Costs)

lan900 Event	lan900 Normalized Port	lan901 Normalized Port	Active Port
	Cost	Cost
Failover group constructed1	1/300, or .003	1/200, or .005	lan9002
1 port fails	1/200, or .005	1/200, or .005	lan9003
1 port fails	1/100, or .01	1/200, or .005	lan9014
DOWN port becomes active	1/200, or .005	1/200, or .005	lan9005

1All ports in the link aggregates are operational.

2 Normalized port cost is lower than lan901.

3 Normalized port cost is the same, but it has a higher priority than lan901.

4 Normalized port cost is lower than lan900.

5 Normalized port cost is the same, but it has a higher priority than lan901.

If the priorities were the same, lan901 would continue as the active port until the third port in lan900 became active.

Example 2

You want to configure a failover group (lan902) for proactive failover. You decide that the failover group consists of two link aggregates: lan900 and lan901. The lan900 aggregate consists of ports 2 and 3; the lan901 aggregate consists of ports 4 and 5. Ports 2, 3, 4, and 5 have speeds of 100 Mb/s. In addition, the link aggregates are connected to different routers using different speeds to connect to the network.

To configure the failover group for proactive failover, do the following:

1.Determine network efficiency.

In this example, you determine that the router connected to lan900 is 1.5 times more efficient at delivering traffic to the network than the router connected to lan901. You assign lan900 a cost of 1 and lan901 a cost of 1.5. However, you must express cost values in the lanconfig.ascii file using whole numbers (no decimal points). The ratio of 1 to 1.5 is the same as the ratio of 2 to 3. Therefore, lan900 has a cost of 2 and lan901 has a cost of 3.

2.Assign a priority to the aggregates.

Because you prefer lan900 over lan901, you assign lan900 a priority of 8 and lan901 a priority of 7. That way, if both ports have the same normalized port cost, lan900 has precedence over lan901.

Editing Configuration Files for Link Aggregates 111