09-16-2011 12:29 PM - edited 03-07-2019 02:16 AM
Hello all,
I have been trying to figure this issue out and hoping I can get clarity here from some of you that that have had experience with this subject.
Background:
I have an application that is marking using DSCP values. All of the switchports are configured for Layer 2 and I would like to leverage queueing.
As I understand it, DSCP is useless for queueing as it only cares about COS.
so I believe I need to create a table-map. Here is my table map for DSCP to COS
table-map dscp-cos-map-qos
default copy
from 0 to 1
from 18 to 2
from 26 to 3
from 34 to 4
from 46 to 5
according to the documentation, I can then use this table-map in this manner:
switch(config)# policy-map policy1 switch
switch(config-pmap-qos)# class class1 switch
switch(config-pmap-c-qos)# set cos dscp cos-dscp-map
found here http://www.cisco.com/en/US/docs/switches/datacenter/sw/5_x/nx-os/qos/configuration/guide/marking.html#wp1056920http://www.cisco.com/en/US/docs/switches/datacenter/sw/5_x/nx-os/qos/configuration/guide/marking.html#wp1062805
However,
I try this on the actual Nexus (running 5.1.4)
and this is what I get:
test1(config)# policy-map qos_apps
test1(config-pmap-qos)# class
class-default qos_apps type
test1(config-pmap-qos)# class qos_apps
test(config-pmap-c-qos)# est ?
^
% Invalid command at '^' marker.
test1(config-pmap-c-qos)# set ?
cos IEEE 802.1Q class of service
discard-class Discard class
dscp DSCP in IP(v4) and IPv6 packets
load-sharing Load sharing across ECMP by set out-of-order bit
precedence Precedence in IP(v4) and IPv6 packets
qos-group Qos-group
test(config-pmap-c-qos)# set cos ?
<0-7> 802.1Q Class of Service value
cos IEEE 802.1Q class of service
It looks like I cannot map Cos to DSCP because if I try it, it rejects:
test# set cos dscp
^
% Invalid number at '^' marker.
test(config-pmap-c-qos)#
am I missing something?
thanks!
09-16-2011 05:38 PM
With nexus there are default classes for ingress can not be removed but you can change it and also they difere depending on the I/O model used like the 10G M1 has 8q4t queuing classes
So I would say follow the best practice recommendations from cisco when you implement your N7K qos
Also for your above question see the guide for older versio. I think it describe it clearer as you might need to use class and policy type of qos
Hope this help
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