QoS on Nexus 3K

[Iulian Vaideanu]

I'm having a bit of a trouble prioritizing some multicast traffic through a Nexus 3064 - basically I need ~700Mbps of multicast traffic entering Ethernet1/45 (speed 10G) to be sent without any drops to Ethernet1/16 (speed 1G) which gets congested from time to time.  That traffic comes with IP precedence 4, so I assign that precedence to qos-group 1 on the ingress of E1/45, then put qos-group 1 in the priority queue on the egress of E1/16 - I must be missing something though since, although "show policy-map interface ethernet 1/45" shows incrementing matches for the relevant class-map, multicast traffic keeps getting dropped on E1/16 ("show queuing interface ethernet 1/16" shows the same number of dropped multicast pkts as "show interface ethernet 1/16" shows output discards).

I'm including the output of "show running-config ipqos", maybe someone can tell me what I'm missing...  thank you.

version 7.0(3)I4(8a)
class-map type qos match-any cqos-ipprec4
  match precedence 4
class-map type queuing cque-ipprec4
  match qos-group 1
policy-map type qos pqos-ipprec4
  class cqos-ipprec4
    set qos-group 1
  class class-default
policy-map type queuing pque-ipprec4
  class type queuing cque-ipprec4
    priority
    bandwidth percent 70
  class type queuing class-default
    bandwidth percent 30
class-map type network-qos cnet-qos-group-1
  match qos-group 1
policy-map type network-qos jumbo-frames
  class type network-qos class-default
    mtu 9216
policy-map type network-qos pnet-qos-groups
  class type network-qos cnet-qos-group-1
    mtu 9216
  class type network-qos class-default
    mtu 9216
system qos
  service-policy type network-qos pnet-qos-groups
qos qos-policies statistics


interface Ethernet1/16
  service-policy type queuing output pque-ipprec4

interface Ethernet1/45
  service-policy type qos input pqos-ipprec4

[Georg Pauwen]

Hello,

are interfaces Ethernet1/16 and Ethernet1/45 layer 3 ports (no switchport) ?

[Iulian Vaideanu]

Hi Georg,
No, they are trunk switchports (everything on that Nexus is layer2, except management of course).

[Iulian Vaideanu]

It seems that qos-group 1 is somehow special (for example, WRED and ECN are not avaialble for it), so I changed it to qos-group 4.  There is a difference (with qos-group 1 "show queuing interface e1/16" would report identical multicast counters for qos groups 0 and 1, while now they differ), but still traffic is only dropped from qos group 4 (which is supposed to be assigned to the priority queue):

# show interface ethernet 1/16 | i discard
    0 input with dribble  0 input discard
    0 lost carrier  0 no carrier  0 babble  2364 output discard

# show queuing interface ethernet 1/16 | i QOS|\+---|cast|Dropped
+-------------------------------------------------------------------+
|                              QOS GROUP 0                          |
+-------------------------------------------------------------------+
|                |  Unicast       | OOBFC Unicast  |  Multicast     |
+-------------------------------------------------------------------+
|   Dropped Pkts |               0|               0|               0|
|   Dropped Byts |               0|               0|               0|
+-------------------------------------------------------------------+
|                              QOS GROUP 4                          |
+-------------------------------------------------------------------+
|                |  Unicast       | OOBFC Unicast  |  Multicast     |
+-------------------------------------------------------------------+
|   Dropped Pkts |               0|               0|            2364|
|   Dropped Byts |               0|               0|         3229224|
+-------------------------------------------------------------------+