Figure 29 Logical Isls Connecting Logical Switches - Brocade Communications Systems 1606 Administrator's Manual

Traffic between the logical switches can now flow across this XISL. The traffic can flow only
between logical switches with the same fabric ID. For example, traffic can flow between Logical
Switch 2 in chassis 1 and Logical switch 6 in chassis 2, because they both have fabric ID 1. Traffic
cannot flow between Logical switch 2 and Logical switch 7, because they have different fabric IDs
(and are thus in different fabrics).
Think of the logical switches as being connected with logical ISLs, as shown in
diagram, the logical ISLs are not connected to ports because they are not physical cables. They are
just a logical representation of the switch connections that are allowed by the XISL.
FIGURE 29
To be able to use the XISL, the logical switches must be configured to allow XISL use. By default,
they are configured to do so; you can change this setting, however, using the procedure described
in "Configuring a logical switch to use XISLs"
NOTE
The default logical switch in the Brocade DCX or DCX-4S cannot use XISLs.
You can also connect logical switches using a combination of ISLs and XISLs, as shown in
on page 218. In this diagram, traffic between the logical switches in fabric 1 can travel over either
the ISL or the XISL. Traffic between the other logical switches travels only over the XISL.
Fabric OS Administrator's Guide
53-1001763-01
Physical chassis 1
Logical switch 1 P1
(Default logical switch)
Fabric ID 128
P2
Logical switch 2
Fabric ID 1
Logical switch 3
Fabric ID 15
P5
P6
Base switch
Fabric ID 8
Logical ISLs connecting logical switches
Logical fabric overview
Physical chassis 2
P1
Logical ISL
(Default logical switch)
P2
Logical ISL
Logical ISL
P6
XISL
P8
on page 232.
10
Figure 29. In this
Logical switch 5
Fabric ID 128
Logical switch 6
Fabric ID 1
P4
P7
Logical switch 7
Fabric ID 15
P9
Base switch
Fabric ID 8
Figure 30
217