272 Fabric OS Administrator’s Guide
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Enhanced TI zones
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Enhanced TI zones

Prior to Fabric OS v6.4.0, a port could be in only one TI zone at a time. Starting in Fabric OS v6.4.0,
ports can be in multiple TI zones at the same time. Zones with overlapping port members are
called enhanced TI zones (ETIZ).
Figure 38 shows an example of two TI zones. Because these TI zones have an overlapping port
(3,8), they are enhanced TI zones.
FIGURE 38 Enhanced TI zones
Enhanced TI zones are especially useful in FICON fabrics. See the FICON Administrator’s Guide for
example topologies using enhanced TI zones.
When you create TI zones, ensure that all traffic from a port to all destinations on a remote domain
have the same path. You cannot create separate paths from a local port to two or more devices on
the same remote domain.
Figure 39 on page 273 shows two enhanced TI zones that are configured incorrectly. If the TI zones
are configured with failover disabled, some traffic will be dropped. If the TI zones are configured
with failover enabled, all traffic will go through, but half of the traffic will be routed incorrectly
according to the TI zone definitions.
This example contains two enhanced TI zones:
ETIZ 1 contains (1,1), (1,2), (3,6), (3,8)
ETIZ 2 contains (2,1), (2,2), (1,4), (1,3), (3,7), (3,8)
In this example traffic from the Target to Domain 2 is routed correctly. Only one TI zone describes a
path to Domain 2. However, both TI zones describe different, valid paths from the Target to Domain
1. Only one path will be able to get to (1,1). Traffic from port (3,8) cannot be routed to Domain 1
over both (3,6) and (3,7), so one port will be chosen. If (3,7) is chosen, frames destined for (1,1)
will be dropped at Domain 1.
7
Domain 1 Domain 3
Domain 2
Host 1
16
= ETIZ 1
28
1
2
Host 2
Target
= ETIZ 2