Enable jumbo frames on interface - Layer 2 - Nexus 31xx series

[nhgri-datacenter]

Hi,

We would like to verify that jumbo frames are enabled and MTU size is to 9216, for all Layer 2 switches in our data center. 

QUESTION: Is there anyway to set the interface MTU to 9216 bytes??

We have run the following commands:

1.    # show  run all | in jumbomtu

system jumbomtu 9216

policy-map type network-qos jumbo

  service-policy type network-qos jumbo

2.    # show run ipqos

policy-map type network-qos jumbo

  class type network-qos class-default

    mtu 9216

system qos

  service-policy type network-qos jumbo

3.   # show queueing interface e1/32

Ethernet1/32 queuing information:

    qos-group  sched-type  oper-bandwidth

        0       WRR            100

    qos-group 0

    HW MTU: 9216 (9216 configured)

    drop-type: drop, xon: 0, xoff: 0

    Statistics:

        Ucast pkts sent over the port           : 4131595597

4.  # show run | sec policy-map

policy-map type network-qos jumbo

  class type network-qos class-default

    mtu 9216

5.  # show run | sec “system qos”

system qos

  service-policy type network-qos jumbo

6. ***For all interfaces though, we get the below output:****

# show interface e1/32 | in MTU

 MTU 1500 bytes, BW 40000000 Kbit, DLY 10 usec

Thank you.

[Reza Sharifi]

Hi,

The MTU can only be setup for the entire switch and not per interface.

HTH

[nhgri-datacenter]

Based on the outputs above, can we declare that jumbo frames has been enabled on this Layer 2 switch.

Does VLAN MTU config apply to Layer 2 switching?

Thanks.

[Reza Sharifi]

Yes, based on the output jumbo frame is enabled for the switch. 

Does VLAN MTU config apply to Layer 2 switching?

On this platform, I don't think you can enable it per vlan.  I think you can only do it for the whole switch.

HTH

[nhgri-datacenter]

Thank you!