Fabric OS Administrator's Guide v7.0.0 (53-1002148-02, June 2011)

Fabric OS Administrator’s Guide 435
53-1002148-02
ICL trunking
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ICL trunking
ICL trunking is configured on an inter-chassis link (ICL) between two enterprise-class platforms and
is applicable only to ports on the core blades.
ICL trunks automatically form on the ICLs when you install the Trunking license on each platform.
Supported platforms for ICL trunking
You can have ICL trunks only between platforms with the same ASIC type. The Brocade DCX and
DCX-4S have the same ASIC type, and the Brocade DCX 8510 family has the same ASIC type. So
you can have ICL trunks between the following platforms:
• DCX to DCX
• DCX to DCX-4S
• DCX-4S to DCX-4S
• DCX 8510-8 to DCX 8510-8
• DCX 8510-8 to DCX 8510-4
• DCX 8510-4 to DCX 8510-4
ICL trunking on the Brocade DCX 8510-8 and 8510-4
The Brocade DCX 8510-8 has 4 port groups on the CR16-8 core blade. The Brocade DCX 8510-4
has 2 port groups on the CR16-4 core blade. Each port group has 4 QSFP connectors, and each
QSFP connector maps to 4 user ports.
Each of the 4 user ports in a QSFP terminates on a different ASIC, so a trunk cannot be formed
among these ports.
To establish ICL trunking between platforms in the Brocade DCX 8510 family, follow these
configuration rules:
• You need at least 2 ICLs between the platforms. A single ICL does not enable trunking.
Each QSFP has four ports. However, these ports cannot form a trunk with each other, but can
form trunks only with corresponding ports on another QSFP.
• You can have a maximum of 4 ports in an ICL trunk.
• You can have a maximum of 8 4-port trunks to a neighboring domain. Each core blade can
have a maximum of 4 ICLs to a neighboring domain.
• The QSFP cables must be connected to the same trunk group on each platform.
For example, Figure 71 shows the core blades on two Brocade DCX 8510-8 platforms, connected
with four ICLs. Only two of the ICLs form trunks. The ICLs indicated by solid red lines form trunks
because the QSFP cables are connected to the same trunk group on each platform. The ICLs
indicated by green and blue dashed lines do not form trunks because, although they are connected
to the same trunk group on Chassis 1, they are connected to different trunk groups on Chassis 2.
In Figure 71, the QSFP cables (solid red lines) form four ICL trunks with two ports in each trunk. If
you added another QSFP cable connecting the same two trunk groups, you would still have four ICL
trunks, but they would now have three ports in each trunk.