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FC-FC Routing and Virtual Fabrics 21
•EX_Ports can connect to a logical switch that is in the same chassis or a different chassis.
However, the FID of the EX_Port must be set to a different value than the FID of the logical
switch to which it connects.
•EX_Ports and VEX_Ports — those in FC routers and those in a base switch — cannot connect to
any edge fabric with logical switches configured to use XISLs.
If you connect an EX_Port or VEX_Port to an edge fabric, you must ensure that there are no
logical switches with XISL use enabled in that edge fabric. If any logical switch in the edge
fabric allows XISL use, then the EX_Port or VEX_Port is disabled. See “Configuring a logical
switch to use XISLs” on page 232 for instructions on disallowing XISL use.
Since XISL use is disallowed, dedicated links must be configured to route traffic across
switches in the same logical fabric, as shown in Figure 26 on page 215.
ATTENTION
If you connect an EX_Port or VEX_Port from an FC router running Fabric OS v6.1.x or earlier to a
logical switch that allows XISL use, the EX_Port or VEX_Port is not disabled; however, this
configuration is not supported.
•Backbone-to-edge routing is not supported in the base switch. See “Backbone-to-edge routing
with Virtual Fabrics” on page 494 for information about how to configure FC routers to allow
backbone-to-edge routing with Virtual Fabrics.
•If you connect an FC router in legacy mode to a base switch, you must set the backbone FID of
the FC router to be the same as that of the base switch.
•All FCR commands can be executed only in the base switch context.
•The fcrConfigure command is not allowed when Virtual Fabrics is enabled. Instead, use the
lsCfg command to configure the FID.

Logical switch configuration for FC routing

For example, Figure 76 shows two chassis partitioned into logical switches. This configuration
allows the device in Fabric 128 to communicate with the device in Fabric 15 without merging the
fabrics. Note the following:
•The base switch in Physical chassis 1 serves as an FC router and contains EX_Ports that
connect to logical switches in the two edge fabrics, Fabric 128 and Fabric 15.
•The other logical switches in Fabric 128 and Fabric 15 must be connected with physical ISLs,
and do not use the XISL connection in the base fabric.
•The logical switches in Fabric 1 are configured to allow XISL use. You cannot connect an
EX_Port to these logical switches, so the device in Fabric 1 cannot communicate with the other
two devices.