Fabric OS Administrator's Guide v7.0.0 (53-1002148-02, June 2011)

Fabric OS Administrator’s Guide 275
53-1002148-02
Traffic Isolation Zoning overview
12
If the dedicated ISL is not the lowest cost path ISL, then the following rules apply:
• If failover is enabled, the traffic path for the TI zone is broken, and TI zone traffic uses the
lowest cost path instead.
• If failover is disabled, the TI zone traffic is blocked.
If the dedicated ISL is the only lowest cost path ISL, then the following rules apply:
• 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 38, 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 38 Dedicated path is the only shortest path
In Figure 39 on page 276, 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.
7
12
3
14
15
16
Domain 1 Domain 3
Domain 4
Domain 2
8
19
6
9
5
= Dedicated Path
= Ports in the TI zone