Specifications

5-3
Cisco SN 5428-2 Storage Router Software Configuration Guide
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Chapter 5 Configuring Fibre Channel Interfaces
Configuring FC Interfaces
• GS-3 management server commands enabled
• Port type of generic loop, which enables automatic selection of port type as Fabric (F_Port), Fabric
Loop (FL_Port or public loop) or Expansion (E_Port or switch to switch)
• Credit extension is not enabled (ext-credit is 0)
Configuring an FC Port Type
To configure an FC port type, select the appropriate port type based on the connected equipment, as
described in Table 5-1 on page 5-2.
Note If you are going to attach to a Fibre Channel fabric through an inter-switch link or by connecting to
another SN 5428-2, verify that the named interface port type is set to generic loop (GL_Port), using the
show interface command. If it is not, you must change the FC interface port type to GL_Port and reset
the interface, as shown in the following procedure.
Use the following procedure to configure and reset a port type for an FC interface. Resetting the port
type ensures that the port is configured correctly with the connected equipment. In this example, fc3 is
the interface that is connected to your Fibre Channel switched fabric, and it is being set to port type
gl-port.
Note Removing the cable to the FC interface port and re-attaching the cable also resets the interface.
Configuring a Donor Port to Extend Buffer Credits
You can configure one or more FC ports as donor ports to extend buffer credits to other FC ports. This
feature is useful for counteracting performance degradation caused by transmission delay to distant
devices.
The sole purpose of a donor port is to extend buffer credits to selected FC ports in the SN 5428-2 Storage
Router; a donor port cannot provide connectivity to an FC device.
To donate credits, the donor port type must be donor. To receive credits, a selected FC port must be
configured to receive extended credits and must be one of the following types: E_Port, F_Port or G_Port.
A port with a running loop port type (FL_Port, GL_Port, or TL_Port) cannot receive donated credits.
Each donor port donates 11 buffer credits, all of which must go to a single recipient port configured for
credit extension.
Use the following procedure to configure a port to receive extended credits and to configure the donor
port.
Command Description
Step 1
enable Enter Administrator mode.
Step 2
interface fc3 type gl-port Specify the port type to be used for the specified port.
See the interface fc? type command in Chapter 12, “Command
Line Interface Reference,” for additional port types and details.
Step 3
interface fc3 reset Resets the FC interface.