HP Fabric OS v7.0.1, Administrator'S Manual

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Fabric OS Administrator’s Guide 473
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Fibre Channel routing concepts
24
Phantom domains
A phantom domain is a domain created by the Fibre Channel router. The FC router creates two
types of phantom domains: front phantom domains and translate phantom domains.
A front phantom domain , or front domain , is a domain that is projected from the FC router to the
edge fabric. There is one front phantom domain from each FC router to an edge fabric, regardless
of the number of EX_Ports connected from that router to the edge fabric. Another FC router
connected to the same edge fabric projects a different front phantom domain.
A translate phantom domain , also referred to as translate domain or xlate domain , is a router
virtual domain that represents an entire fabric. The EX_Ports present xlate domains in edge fabrics
as being topologically behind the front domains; if the xlate domain is in a backbone fabric, then it
is topologically present behind the FC router because there is no front domain in a backbone fabric.
If an FC router is attached to an edge fabric using an EX_Port, it creates xlate domains in the fabric
corresponding to the imported edge fabrics with active LSANs defined. If you import devices into
the backbone fabric, then an xlate domain is created in the backbone device in addition to the one
in the edge fabric.
Figure 76 shows a sample physical topology. This figure shows four FC routers in a backbone fabric
and four edge fabrics connected to the FC routers.
FIGURE 76 Sample topology (physical topology)
Figure 77 shows a phantom topology for the physical topology shown in Figure 76 . In this figure, the
dashed lines and shapes represent the phantom topology from the perspective of Fabric 1. Fabrics
2 and 3 also see phantom topologies, but they are not shown in this example. In this figure, note
the following:
•
Front domain 1 and Front domain 2 are front domains for EX_Ports connecting to Fabric 1.
There is one front domain for each FC router that is connected to Fabric 1.
•
Xlate domain 1 and Xlate domain 2 represent Fabrics 2 and 3, respectively. No xlate domain is
created for Fabric 4 because there are no LSAN devices in Fabric 4.
•
Target 1’, Target 2’, and Target 3’ are proxy devices for Target 1, Target 2, and Target 3,
respectively.
Fabric 1 Fabric 2 Fabric 3
Fabric 4
Host Target 1 Target 2 Target 3
FC router 1 FC router 4 FC router 3 FC router 2
EX
E
EX
EX
EX EX
EX
EX
E
E
E
E
E
E