Figure 29, Logical i – Dell POWEREDGE M1000E User Manual
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Fabric OS Administrator’s Guide
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Logical fabric overview
10
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
. In this
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
Logical ISLs connecting logical switches
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.
Base switch
Fabric ID 8
P9
Logical switch 7
Fabric ID 15
P7
Logical switch 6
Fabric ID 1
P4
Logical switch 5
(Default logical switch)
Fabric ID 128
Physical chassis 2
Base switch
Fabric ID 8
P6
Logical switch 3
Fabric ID 15
P5
Logical switch 2
Fabric ID 1
P2
Logical switch 1
(Default logical switch)
Fabric ID 128
P1
Physical chassis 1
P8
P6
P2
P1
XISL
Logical ISL
Logical ISL
Logical ISL