Configuring Fibre Channel Interfaces
Buffer-to-Buffer Credits
Buffer-to-buffer credits (BB_credits) are a flow-control mechanism to ensure that Fibre Channel interfaces
do not drop frames. BB_credits are negotiated on a per-hop basis.
In Cisco Nexus 5000 Series switches, the BB_credit mechanism is used on Fibre Channel interfaces but not
on virtual Fibre Channel interfaces. Virtual Fibre Channel interfaces provide flow control based on capabilities
of the underlying physical Ethernet interface.
The receive BB_credit value (fcrxbbcredit) may be configured for each Fibre Channel interface. In most cases,
you do not need to modify the default configuration.
Note
The receive BB_credit values depend on the port mode. For physical Fibre Channel interfaces, the default
value is 16 for F mode and E mode interfaces. This value can be changed as required. The maximum value
is 64.
For virtual Fibre Channel interfaces, BB_credits are not used.
Configuring Fibre Channel Interfaces
Configuring a Fibre Channel Interface
To configure a Fibre Channel interface, perform this task:
SUMMARY STEPS
1. switch# configuration terminal
2. switch(config)# interface {fc slot/port}|{vfc vfc-id}
DETAILED STEPS
Command or Action
Step 1
switch# configuration terminal
Step 2
switch(config)# interface {fc
slot/port}|{vfc vfc-id}
Configuring a Range of Fibre Channel Interfaces
To configure a range of Fibre Channel interfaces, perform this task:
Cisco Nexus 5000 Series NX-OS SAN Switching Configuration Guide
14
Purpose
Enters configuration mode.
Selects a Fibre Channel interface and enters interface configuration mode.
Note
When a Fibre Channel interface is configured, it is automatically
assigned a unique world wide name (WWN). If the interface's
operational state is up, it is also assigned a Fibre Channel ID (FC
ID).
Configuring Fibre Channel Interfaces
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