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

Fabric OS Administrator’s Guide 69
53-1002148-02
Inter-chassis links
4
The following ICL connections are not allowed:
• ICL0 ports to ICL0 ports
• ICL1 ports to ICL1 ports
For detailed ICL connection information, refer to the Brocade DCX Backbone Hardware Reference
Manual.
ICL ports can be used only with an ICL license. For more information on how license enforcement
occurs, see Chapter 18, “Administering Licensing”. After the addition or removal of a license, the
license enforcement is performed on the ICL ports only when you issue the portDisable or
portEnable commands on the switch for the ports. All ICL ports must be disabled and then
re-enabled for the license to take effect. An ICL license must be installed on both platforms forming
the ICL connection.
Each ICL connector port has two LEDs; a Status LED and an Attention LED. Table 9 describes the
behavior of the LEDs.
The ICL ports appear as regular ports, with some restrictions. All port parameters associated with
ICL ports are static and all portCfg commands are blocked from changing any of the ICL port
parameters. The only management associated with ICL ports and cables is monitoring the status of
the LEDs on the ICL ports and any maintenance if the Attention LED is blinking yellow. For
additional information about the LED status for blades and ports, refer to the Brocade DCX
Backbone Hardware Reference Manual.
When you connect two Brocade Backbones, the following features are supported:
• 8 Gbps speed
• Trunking
• Buffer-to-buffer credit sharing
• QoS
Supported topologies
A triangular topology is supported among three Brocade DCX or DCX-4S chassis. During an ICL
break, the chassis that has the connections of the other two is the main chassis. Any error
messages relating to a break in the topology appear in the RASlog of the main chassis.
If one ICL is broken but there is a regular ISL, the triangular topology holds given that the ISL cost is
lower than the total cost through the ICL linear topology. If a direct ICL link between two switches is
broken, the triangular topology is considered broken when the ISL path between the two switches is
a multiple hop. In this case, the triangular topology broken message is posted independently of the
TABLE 9 LED behavior
LED Color Description Action
Status
Black No connection with peer blade. NA
Green ICL connection with peer blade is
good.
NA
Attention
Black ICL is fully operational. NA
Blinking Yellow One or more links in the ICL
connection is not operational.
Reconnect the ICL cables
or replace the ICL cables.