This example shows how to remove the queue limit that is set by default on a Cisco Nexus 2248T Fabric
Extender:
switch#
configure terminal
switch(config)#
fex 101
switch(config-fex)#
no hardware N2248T queue-limit 327680
Configuring No-Drop Buffer Thresholds
You can configure the no-drop buffer threshold settings for 3000m lossless Ethernet.
To achieve lossless Ethernet for both directions, the devices connected to the Cisco Nexus device must
have the similar capability. The default buffer and threshold value for the no-drop can ensure lossless
Ethernet for up to 300 meters.
Note
Procedure
Purpose
Command or Action
Enters global configuration mode.
switch#
configure terminal
Step 1
Enters policy-map network-qos class mode and identifies the
policy map assigned to the type network-qos policy map.
switch(config)#
policy-map type
network-qos policy-map name
Step 2
References an existing network QoS class map in a policy map
and enters class mode.
switch(config-pmap-nq)#
class
type network-qos class-map name
Step 3
Specifies the buffer threshold settings for pause and resume
for 3000m lossless Ethernet:
switch(config-pmap-nq-c)#
pause
no-drop buffer-size buffer-size
Step 4
pause-threshold xoff-size
resume-threshold xon-size
•
buffer-size
—
Buffer size for ingress traffic, in bytes. Valid
values are from 10240 to 490880.
On a Cisco Nexus 5020 switch, you can
configure a maximum buffer size of 143680
bytes.
On a Cisco Nexus 5500 Series device, you can
configure a maximum buffer size of 152000
bytes.
Note
•
pause-threshold
—
Specifies the buffer limit at which the
port pauses the peer.
•
xoff-size
—
Buffer limit for pausing, in bytes. Valid values
are 0 to 490880.
On a Cisco Nexus 5020 switch, you can
configure a maximum pause-threshold value of
58860 bytes.
On a Cisco Nexus 5500 Series device, you can
configure a maximum pause-threshold value of
103360 bytes.
Note
Cisco Nexus 5000 NX-OS Quality of Service Configuration Guide, Release 5.1(3)N2(1)
62
OL-26657-01
Configuring Queuing and Flow Control
Configuring No-Drop Buffer Thresholds