HP StorageWorks Fabric OS 6.1.1 administrator guide (5697-0235, December 2009)

Fabric OS 6.1.x administrator guide 293
• If failover is disabled for the TI zone, non-TI zone traffic is halted until the non-dedicated ISL between
Domain 1 and Domain 3 is back online.
FSPF routing rules and Traffic Isolation
All traffic must use the lowest cost path. FSPF routing rules take precedence over the TI zones, as described
in the following situations.
If the dedicated ISL is not the lowest cost path ISL, 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 path ISL is the only lowest cost path ISL, the following rules apply:
• If failover is enabled, both non-TI zone traffic and 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 28, 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 uses 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 28 Dedicated path is the only shortest path.
In Figure 29, 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
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