Brocade Network Advisor SAN User Manual v12.1.0 - Manual (Page 864)

816 Brocade Network Advisor SAN User Manual
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FCIP trunking
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• Consider available WAN bandwidth requirements when configuring failover circuit groups.
Refer to
“Bandwidth calculation during failover” on page 814.
Examples of circuit failover in groups
Tables Table 68 through Table 70 provide examples of how failover occurs on circuits with different
bandwidths configured in failover groups.
Table 68 illustrates circuit failover in a tunnel with two failover groups, each with two circuits. All
data through the tunnel is initially load balanced over Circuits 1 and 2. The following occurs during
circuit failover:
• If circuit 1 fails, circuit 3 becomes active and data is load balanced over circuit 2 and 3.
• If circuit 2 fails, circuit 4 becomes active and data is load balanced over circuit 1 and 4.
• If both circuit 1 and 2 fail, circuit 3 and.4 become active and data is load balanced over both
circuits.
Table 69 illustrates circuit failover in a tunnel with one failover group containing three circuits, In
this case, failover occurs as if circuits are not part of a failover group. Circuit 2 and 3, both with
metric 1, become active only after circuit 1 with metric 0 fails.
Table 70 illustrates circuit failover in a tunnel with circuits in failover groups and circuits that are
not part of failover groups. In this configuration, all data is initially load balanced over circuit.1,
circuit 2, and circuit 3 (when they are all active). The following occurs during circuit failover:
• If circuit1 fails, circuit 4 becomes active and data is load balanced over circuit 2, circuit 3, and
circuit 4.
Reason: Circuit 1 fails over to circuit 4 (both are in failover group 1) and circuit 3 is active with
500Mb bandwidth.
TABLE 68 Tunnel with two failover groups with two circuits
Circuits in tunnel Failover group ID Circuit bandwidth In use for tunnel data
Circuit 1
Metric 0 1 500Mb If active, yes.
Circuit 2
Metric 0 2 1000Mb If active, yes.
Circuit 3
Metric 1 1 500Mb Only when circuit 1
fails.
Circuit 4
Metric 1 2 1000Mb Only when circuit 2
fails.
TABLE 69 Tunnel with one failover groups with three circuits
Circuits in tunnel Failover group ID Circuit bandwidth In use for tunnel data
Circuit 1
Metric 0 1 1000Mb If active, yes.
Circuit 2
Metric 1 1 500Mb Only when circuit 1
fails.
Circuit 3
Metric 1 1 500Mb Only when circuit 1
fails.