Fabric OS Administrator's Guide v6.4.0 (53-1001763-01, June 2010)

212 Fabric OS Administrator’s Guide
53-1001763-01
Logical switch overview
10
Logical switches and fabric IDs
When you create a logical switch, you must assign it a fabric ID (FID). The fabric ID uniquely
identifies each logical switch within a chassis and indicates to which fabric the logical switch
belongs. You cannot define multiple logical switches with the same fabric ID within the chassis.
In Figure 22, logical switches 2, 3, 4, and 5 are assigned FIDs of 1, 15, 8, and 20, respectively.
These logical switches belong to different fabrics, even though they are in the same physical
chassis. For example, you could not assign logical switch 5 a fabric ID of 15, because logical switch
3 is already assigned FID 15 in the chassis. Each logical switch must have a unique fabric ID within
the chassis.
The default logical switch is initially assigned FID 128. You can change this value later.
NOTE
Each logical switch is assigned one and only one FID. The FID identifies the logical fabric to which
the logical switch belongs.
FIGURE 22 Fabric IDs assigned to logical switches
Port assignment in logical switches
Initially, all ports belong to the default logical switch. When you create additional logical switches,
they are empty and you must assign ports to those logical switches. As you assign ports to a logical
switch, the ports are moved from the default logical switch to the newly created logical switch. A
given port can be in only one logical switch.
In Figure 23 on page 213, the default logical switch initially has 10 ports, labeled P0 through P9.
After logical switches are created, the ports are assigned to specific logical switches. Note that
ports 0, 1, 7, and 8 have not been assigned to a logical switch and so remain assigned to the
default logical switch.
Logical switch 5
(FID = 20)
Physical chassis
Logical switch 1
(Default logical switch)
(FID = 128)
Logical switch 2
(FID = 1)
Logical switch 3
(FID = 15)
Logical switch 4
(FID = 8)