Jumboframes over L2 trunks

[torstensson]

Hi,

I have a question regarding jumboframes. At the moment we have done no changes to the MTU sizes, it's all default. Now we will implement NSX-T and jumboframes are needed, MTU size 9216 that is. The jpeg attached shows the current setup, between switch 1 and 2 we have a bunch of VLANs handling various traffic at the moment and my intial idea was to just add the new VLANs that will be used by NSX-T. But after been thinking a little I'm suspecting that I need new dedicated interfaces all the way from Switch 1 -> Core 1 -> Core 2 -> Switch 2.

Or can I just add the new VLANs with a different MTU size on the trunks?

[Reza Sharifi]

Hi,

Not sure exactly what type of Nexus switch you are using. For larger models like 6k, 7k, etc... you can enable it per interface. On the other hand, smaller models like the 5ks Jumbo frame is only supported globally, meaning you have to enable it for the entire switch.

HTH

[torstensson]

Hi,

The core is 7200 and the "top of rack" devices are 9300. So I should just be able to enable it per interface in that case? But I can't just add the new VLANs to the current uplink channel-group interface right? What are the commands in that case? Can't seem to find anything...

[Reza Sharifi]

Hi,

On the 9300, you can apply it per interface.

example:

interface e1/0

mtu 9216

verify with "sh interface e1/0"

should work the same way for PO interfaces.

HTH

[paul driver · Accepted solution]

Hello

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@torstensson wrote:

But after been thinking a little I'm suspecting that I need new dedicated interfaces all the way from Switch 1 -> Core 1 -> Core 2 -> Switch 2.

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TBH i dont thiink the above would be applicable applied the LAN as a whole espeacilly if you have an large LAN. However based the topology diagram your have shown id would say it be okay between DC VPC's and within and between the NSX-T environment and the switch1/2 VPC switches