Brocade FICON Administrator’s Guide (Supporting Fabric OS v7.3.0) - Manual (Page 84)

The figure below shows that the setup allows a source device to reach two separate destinations over
exclusive, one-hop paths, while preventing the source device from taking the two-hop path in the event
of a failure.
FIGURE 22 Triangular topology with Enhanced TI Zones
The preceding figure shows the following TI Zone definitions for the triangular topology:
• Blue Zone includes the channel, ISL 1, and CU A.
• Green Zone includes the channel, ISL 2, and CU B.
• Red Zone includes the CU A, ISL 3, and CU B.
Using these definitions with failover disabled, the topology achieves the desired behavior. The channel
can reach CU A only over ISL 1 and CU B only over ISL 2. If either ISL should fail, connectivity to the
destination with the failed ISL is prevented because the exclusive path has failed.
Maintaining and Troubleshooting FICON
82 FICON Administrator's Guide
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