Fabric OS Administrator’s Guide 223
53-1001763-02
Enabling Virtual Fabrics mode 10
Following are restrictions on the default logical switch in the Brocade DCX and DCX-4S:
The default logical switch cannot use extended ISLs (XISLs).
The default logical switch cannot be a base switch.
Following are restrictions on XISL use. To allow or disallow XISL use for a logical switch, see
“Configuring a logical switch to use XISLs” on page 232. XISL use is not permitted in any of the
following scenarios:
The logical switch is FICON CUP enabled.
The logical switch is operating in interoperability mode 2 or 3.
The logical switch has ICL ports.
The logical switch is an edge switch for an FC router.
The logical switch is using GbE ports (VE_Ports).
The logical switch is the default logical switch in the Brocade DCX or DCX-4S.

Restrictions on moving ports

The following are restrictions on moving ports among logical switches:
FC ports cannot be moved if any one of the following features is enabled:
-Long distance
-QoS
-Fport buffers
-Fport trunking
Before moving VE_Ports, you must remove the VE_Port tunnel configuration.
VE_Ports on the FX8-24 blade can be moved to any logical switch independent of the location
of the physical GE port.

Enabling Virtual Fabrics mode

A fabric is said to be in Virtual Fabrics mode (VF mode) when the Virtual Fabrics feature is enabled.
Before you can use the Virtual Fabrics features, such as logical switch and logical fabric, you must
enable VF mode.
VF mode is disabled by default on switches that you upgrade to Fabric OS 6.2.0 or later. VF mode is
enabled by default on a new chassis.
NOTE
When you enable VF mode, the CPs are rebooted and all EX_Ports are disabled after the reboot.
Brocade 5100 3
Brocade VA-40FC 3
TABLE 47 Maximum number of logical switches per chassis (Continued)
Platform Maximum number of logical switches