Chapter 1
Configuring Fibre Channel Interfaces
S e n d f e e d b a c k t o n x 5 0 0 0 - d o c f e e d b a c k @ c i s c o . c o m
Command
Step 3
switch(config-if)# switchport speed
1000
switch(config-if)# no switchport
speed
Autosensing
Autosensing speed is enabled on all 4-Gbps interfaces by default. This configuration enables the
interfaces to operate at speeds of 1 Gbps, 2 Gbps, or 4 Gbps on the 4-Gbps ports. When autosensing is
enabled for an interface operating in dedicated rate mode, 4-Gbps of bandwidth is reserved, even if the
port negotiates at an operating speed of 1-Gbps or 2-Gbps.
Configuring SD Port Frame Encapsulation
The switchport encap eisl command only applies to SD port interfaces. This command determines the
frame format for all frames transmitted by the interface in SD port mode. If the encapsulation is set to
EISL, all outgoing frames are transmitted in the EISL frame format, for all SPAN sources.
The switchport encap eisl command is disabled by default. If you enable encapsulation, all outgoing
frames are encapsulated, and you will see a new line (Encapsulation is eisl) in the show interface
SD_port_interface command output.
Configuring Receive Data Field Size
You can configure the receive data field size for native Fibre Channel interfaces (but not for virtual Fibre
Channel interfaces). If the default data field size is 2112 bytes, the frame length will be 2148 bytes.
To configure the receive data field size, perform this task:
Command
Step 1
switch# configuration terminal
Step 2
switch(config)# interface fc
slot/port
Step 3
switch(config-if)# switchport
fcrxbufsize 2000
Understanding Bit Error Thresholds
The bit error rate threshold is used by the switch to detect an increased error rate before performance
degradation seriously affects traffic.
OL-16597-01
Purpose
Configures the port speed of the interface to 1000 Mbps.
The number indicates the speed in megabits per second
(Mbps). You can set the speed to 1000 (for 1-Gbps
interfaces), 2000 (for 2-Gbps interfaces), 4000 (for
4-Gbps interfaces), or auto (default).
Reverts the factory default (auto) administrative speed of
the interface.
Purpose
Enters configuration mode.
Selects a Fibre Channel interface and enters interface
configuration mode.
Reduces the data field size for the selected interface to
2000 bytes. The default is 2112 bytes and the range is
from 256 to 2112 bytes.
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
Configuring Fibre Channel Interfaces
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