Section C-3. Catalyst 6000 Switch Fabric Module

C-3. Catalyst 6000 Switch Fabric Module

• The SFM provides a 256 Gbps crossbar switching fabric. It dedicates two 8 Gbps ports to each module in a Catalyst 6500 chassis. (Each port operates at 16 Gbps full-duplex.)

• Fabric-enabled modules can connect to only one of the two dedicated SFM ports. Fabric-only modules can connect to both SFM ports.

• The SFM provides several modes of connectivity between modules:

  - Flow-through mode Used when nonfabric-enabled modules are installed; data passes through the normal backplane buses.
  
  

  - Truncated mode Used when fabric-enabled modules are communicating, but some nonfabric-enabled modules are installed. Data passes through a fabric channel unless a nonfabric-enabled module is involved.
  
  

  - Compact mode Used when only fabric-enabled modules are installed in the switch. Data passes through a fabric channel as a compact version, yielding the best switching performance.
  
  

• Two SFMs can be installed in a switch for redundancy. The SFM in the upper slot functions as the primary, and the SFM in the lower slot as the secondary.

• Refer to Chapter 2, "Switch Functionality" for more information about the Catalyst 6000 family architecture.

Configuration

1.

(Optional) Choose a switching mode:

COS	set system switchmode allow {truncated | bus-only}
IOS	N/A

The switch can allow the truncated mode (the default) to be used, if a low number of nonfabric-enabled modules are installed. If all the modules are fabric-enabled, the SFM is allowed to enter compact mode. If the bus-only keyword is used, the SFM is forced into flow-through mode.

2.

(Optional) Choose a fallback mode:

COS	set system crossbar-fallback {bus-mode | none}
IOS	N/A

If the SFM fails, the switch can begin using the normal system bus (bus-mode, the default). If the none keyword is used instead, no traffic will be switched during the SFM failure.

3.

(Optional) Change the LCD display banner:

COS	set banner lcd d message d
IOS	(global) fabric lcd-banner d message d

Normally, the LCD display on SFM modules shows the Cisco Systems logo and name. You can specify a message (text string, up to 800 characters) that begins and ends between the delimiter character d. The delimiter character cannot appear in the message. The message can be entered as one or more lines of text.

You can enter tokens within the message, causing the current token values to display. The switch host name can be substituted for the token $(hostname), and the domain name for the token $(domain).

Displaying Information About the SFM

Table C-3 lists the switch commands that you can use to display helpful information about the SFM.

Table C-3. Commands to Display SFM Information

Display Function	Switch OS	Command
Switch mode and channel status	COS	show fabric channel switchmode [mod]
	IOS	show fabric status [module {mod | all}] show fabric switching-mode [module {mod | all}]
Allowed switch mode	COS	show system switchmode
	IOS	N/A
Fabric counters	COS	show fabric channel counters [mod]
	IOS	show fabric errors [module {mod | all}]
Fabric utilization	COS	show fabric channel utilization
	IOS	show fabric utilization [module {mod | all}]