Brocade Fabric OS Administrators Guide (Supporting Fabric OS v7.3.0) - Manual (Page 345)

• If failover is enabled, non-TI zone traffic as well as TI zone traffic uses the dedicated ISL.
• If failover is disabled, non-TI zone traffic is blocked because it cannot use the dedicated ISL, which is
the lowest cost path.
For example, in Figure 34 , there is a dedicated path between Domain 1 and Domain 3, and another,
non-dedicated, path that passes through Domain 2. If failover is enabled, all traffic will use the
dedicated path, because the non-dedicated path is not the shortest path. If failover is disabled, non-TI
zone traffic is blocked because the non-dedicated path is not the shortest path.
FIGURE 34 Dedicated path is the only shortest path
In Figure 35 , a dedicated path between Domain 1 and Domain 4 exists, but is not the shortest path. In
this situation, if failover is enabled, the TI zone traffic uses the shortest path, even though the E_Ports
are not in the TI zone. If failover is disabled, the TI zone traffic stops until the dedicated path is
configured to be the shortest path.
FIGURE 35 Dedicated path is not the shortest path
For information about setting or displaying the FSPF cost of a path, see the linkCost and
topologyShow commands in the Fabric OS Command Reference.
Traffic Isolation Zoning
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