HP Auto Port Aggregation Administrator's Guide HP-UX 11i v3 (766140-001, March 2014)

Proactive failover examples
Proactive failover relies on measuring and calculating efficiency. The efficiency of a link aggregate
or individual port in a failover group is affected by the following:
• The number of ports in each member of the failover group
• The effective throughput of the switch or router to which the failover group members are
connected
The following examples show how each affects the proactive failover operation.
Example 1
You want to configure a failover group (lan902) for proactive failover. You decide that failover
group consists of two link aggregates: lan900 and lan901. The lan900 aggregate consists of
ports 1, 2, and 3; the lan901 aggregate consists of ports 4 and 5. Ports 1, 2, 3, 4, and 5 have
speeds of 100 Mb/s. In addition, you want the link aggregate with the most operational ports at
any point in time to be the active link in the failover group.
NOTE: You can apply the methodology in this example to failover groups consisting of any
number of link aggregates and ports.
To configure the failover group for proactive failover, do the following:
1. Determine network efficiency.
In this example, you assign both lan900 and lan901 a cost of 1.
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_GROUP lan902
STATIONARY_IP 192.19.20.2
# Primary/Standby Interface Priority : Cost
# –––––––––––––––––––––––+–––––––––––––+––––––––––––––––
PRIMARY lan900 5 : 1
STANDBY lan901 3 : 1
Table 2 lists lan900 events for this example and how proactive failover determines the active port
for lan902.
Table 2 lan900 Events and Proactive Failover (Equal Network Costs)
Active Portlan901 Normalized Port Costlan900 Normalized Port Costlan900 Event
lan900
2
1/200, or .0051/300, or .003Failover group constructed
1
lan900
3
1/200, or .0051/200, or .0051 port fails
lan901
4
1/200, or .0051/100, or .011 port fails
lan900
5
1/200, or .0051/200, or .005DOWN port becomes active
1
All 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.
90 Configuring HP APA by editing files