To Use The Bb_Sc_N Field During Plogi Or Flogi, Follow These Steps; About Receive Data Field Size; Configuring Receive Data Field Size - Cisco MDS 9000 Series Configuration Manual

To use the BB_SC_N field during PLOGI or FLOGI, follow these steps:

S e n d d o c u m e n t a t i o n c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m
For Generation 2 and Generation 3 modules, the BB_SCN on ISLs (E or TE ports) is enabled by default.
This can fail the ISLs if used with optical equipment using distance extension (DE), also known as
buffer-to-buffer credit spoofing.
On Gen-2 module, one port will not come up for the following configuration for all ports:
•
•
•
On Gen-3 module, one or two ports will not come up for the following configuration for first half of the
ports, the second half of the ports or all ports:
•
•
•
When you configure port mode to auto or E and rate-mode to dedicated for all ports in the global buffer
pool, you need to reconfigure buffer credits on one or more ports (other than default).
If you use distance extension (buffer-to-buffer credit spoofing) on ISLs between switches, the BB_SCN
Note
parameter on both sides of the ISL needs to be disabled.
To use the BB_SC_N field during PLOGI or FLOGI, follow these steps:
Command
Step 1
switch# config t
switch(config)#
Step 2
switch(config)# interface fc 1/1
switch(config-if)#
Step 3
switch(config-if)# switchport fcbbscn
switch(config-if)# no switchport fcbbscn

.About Receive Data Field Size

You can also configure the receive data field size for Fibre Channel interfaces. If the default data field
size is 2112 bytes, the frame length will be 2148 bytes.

Configuring Receive Data Field Size

You can also configure the receive data field size for Fibre Channel interfaces. If the default data field
size is 2112 bytes, the frame length will be 2148 bytes.
Cisco MDS 9000 Family NX-OS Interfaces Configuration Guide
4-20
Port Mode: auto or E for all the ports
Rate Mode: dedicated
Buffer Credits: Default value
Port Mode: auto or E for the first half of the ports, the second half of the ports, or for all of the ports
Rate Mode: dedicated
Buffer Credits: default value
Chapter 4
Purpose
Enters configuration mode.
Selects the interface and enters interface
configuration submode.
Enables the use of buffer-to-buffer state change
number for PLOGIs and FLOGIs on the interface.
Disables (default) the use of buffer-to-buffer state
change number for PLOGIs and FLOGIs on the
interface.
OL-19445-02, Cisco MDS NX-OS Release 4.2(x)
Configuring Interface Buffers