Ti Zone Failover; Fspf Routing Rules And Traffic Isolation; Dedicated Path (Shortest Path) - HP A7533A - Brocade 4Gb SAN Switch Base Administrator's Manual

In Figure 21, all traffic entering Domain 1 from N_Port 8 is routed through E_Port 1. Similarly, traffic
entering Domain 3 from E_Port 9 is routed to E_Port 12, and traffic entering Domain 4 from E_Port 7 is
routed to the device through N_Port 6. Traffic coming from other ports in Domain 1 would not use E_Port 1,
but would use E_Port 2 instead.
Other traffic is excluded from the dedicated path as long as other equal-cost routes through the fabric exist.
For example, if the ISL formed by E_Ports "1,2" and "3,10" failed, all traffic between Domains 1 and 3
would use the ISL formed by E_Ports "1,1" and "3,9", even though that ISL is a dedicated path in a TI zone.
Use the zone command to create and manage TI zones. Refer to the Fabric OS Command Reference for
details about the zone command.

TI zone failover

A TI zone can have failover enabled or disabled. If the dedicated path cannot be used and failover is
enabled, the TI zone traffic will use a non-dedicated path instead. If the dedicated path cannot be used
and failover is disabled, the traffic isolation path is broken and traffic for that TI zone is halted until the
dedicated path is fixed.
For example, in
following occurs, depending on the failover option:
• If failover is enabled for the TI zone, the traffic is routed from Domain 1 to Domain 3 through E_Ports
"1,2" and "3,10".
• If failover is disabled for the TI zone, the traffic is halted until the ISL between Domain 1 and Domain 3
is back online.

FSPF routing rules and traffic isolation

FSPF routing rules take precedence over the TI zones, as described in the following situations:
• If other paths through the fabric exist, but they are not the shortest path, then traffic uses the dedicated
ISL.
• If a TI zone creates a path that is not the lowest cost path and failover is enabled, the lowest cost path
is used instead. If failover is not enabled, the traffic path for the TI zone is broken.
For example, in
non-dedicated, path that passes through Domain 2. Since the non-dedicated path is not the shortest path
between Domain 1 and Domain 3, all traffic will use the dedicated path.
Figure 22

Dedicated path (shortest path)

332 Optimizing fabric behavior
Figure 21, if the dedicated ISL between Domain 1 and Domain 3 goes offline, then the
Figure 22, there is a dedicated path between Domain 1 and Domain 3, and another,
Domain 1
8
9
3
15
= Dedicated Path
= Ports in the TI zone
Domain 2
Domain 3
1 9
14
16
Domain 4
12
7
6
5