How to verify jumbo frames on Nexus 5548

[pringleh]

I recently deployed a Nexus 5548. I followed the directions on how to globally enable jumbo frames from the NX-OS configuration guide.

policy-map type network-qos jumbo

     class type network-qos class-default

     mtu 9216

     multi-cast optimize

systesm qos

     service-policy type network-qos jumbo

The Nexus 5548 is connected @ layer 2 to a 6506 via 10Gig. The 6506 10g interface is configured for mtu 9216 as well. I have attempted to issue large pings (9000), but have yet to see any jumbo packets flow over the interface connecting the two switches? Could this have anything to do with the connecting port configured as a trunk (supporting multiple VLANs). The source and destination IPs are in fact on the same VLAN and within the same broadcast range.

Any suggestions on how to verify jumbo frames are indeed setup correctly?

Thanks!

[Oleksandr Nesterov]

Hi.

You can use following command:

#show interfae eth1/1    <--- shows how many jumbo packets were forwarded through the interface (Please be aware that MTU in this output can be incorrect - cosmetic defect. Correct configured mtu on the interface can be viewed using next command)

#show queuing interface eth 1/1 <----  shows configured MTU on the interface

============================

#show interfae ethernet1/1    

Ethernet1/1 is up

...

  RX

      0 unicast packets  1221713 multicast packets  2644 broadcast packets

      1224357 input packets  91236171 bytes

---> 458 jumbo packets  0 storm suppression packets

      0 giants  0 input error  0 short frame  0 overrun   0 underrun

      0 watchdog  0 if down drop

      0 input with dribble  0 input discard

      0 Rx pause

and

#show queuing interface eth 1/1

Ethernet1/1 queuing information:

TX Queuing

qos-group  sched-type  oper-bandwidth

0       WRR             50

1       WRR             50

RX Queuing

qos-group 0

q-size: 243200, HW MTU: 9280 (9216 configured)

drop-type: drop, xon: 0, xoff: 1520

...

Hope that helps.

Alex