Brocade Fabric OS Administrators Guide (Supporting Fabric OS v7.3.0) - Manual (Page 344)

Disabling failover locks the specified route so that only TI zone traffic can use it. Non-TI zone traffic
is excluded from using the dedicated path.
• You should enable failover-enabled TI zones before enabling failover-disabled TI zones, to avoid
dropped frames.
When you issue the cfgEnable command to enable the zone configuration, if you have failover
disabled zones, do the following:
1. Temporarily change failover-disabled TI zones to failover-enabled.
2. Enable the zones (cfgEnable ).
3. Reset all the zones you changed in step 1 to failover-disabled.
4. Enable the zones again (cfgEnable ).
These steps are listed in the procedures in this section.
• It is recommended that TI zone definitions and regular zone definitions match.
• Domain controller frames can use any path between switches. Disabling failover does not affect
Domain Controller connectivity.
For example, in the following figure, if failover is disabled, Domain 2 can continue to send domain
controller frames to Domain 3 and 4, even though the path between Domain 1 and Domain 3 is a
dedicated path. Domain controller frames include zone updates and name server queries.
FIGURE 33 Fabric incorrectly configured for TI zone with failover disabled
• It is recommended that the insistent Domain ID feature be enabled; if a switch changes its active
domain ID, the route is broken. See the configure command in the Fabric OS Command Reference
for information about setting insistent Domain ID.
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, 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:
FSPF routing rules and traffic isolation
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