Cisco Nexus 5000 Series - Configuring Sd Port Frame Encapsulation; Configuring Receive Data Field Size; Understanding Bit Error Thresholds

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Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
OL-16597-01
Chapter 1 Configuring Fibre Channel Interfaces
Configuring Fibre Channel Interfaces
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:
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.
Step 3
switch(config-if)# switchport speed
1000
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).
switch(config-if)# no switchport
speed
Reverts the factory default (auto) administrative speed of
the interface.
Command Purpose
Command Purpose
Step 1
switch# configuration terminal
Enters configuration mode.
Step 2
switch(config)# interface fc
slot/port
Selects a Fibre Channel interface and enters interface
configuration mode.
Step 3
switch(config-if)# switchport
fcrxbufsize 2000
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.