Nexus 5548P - Jumbo Frames

[dclee]

We currently have 2 Nexus 5548P's in VPC mode (etherchannels across both switches) handling all of our backend storage to the Netapp file and VMWare (Nexus 1K) via NFS.

All is working well. Current MTU is 1514 and the storage and servers guys would like to try Jumbo frames.

Jumbo frame config appears to be simple enough to do on the 5548's.

Are they any concerns I need to be aware of, before I give it a try ?

Cheers

Dave

[Walter Dey]

Hi Dave

my 2c

I would use for management, ev. vmotion a old fashioned vswitch, and N1k only for the VM data traffic. Whatever happens with the DVS, you still have connectivity.

It is always questionable, what the benefit of JF is, specially for NFS. I have seen values between 10-25 %; however, I would be paranoid to quote any numbers. The gain for vmotion is definitely great.

Check if JF is working end to end, setting the no fragment bit. Not setting this flag might give you misleading results; a intermediate switch/router might have to fragment.

Btw. Netapp Flexpod CVD mandates Jumbo Frames.

[ygazel]

Hi Dave,

Just make sure you are on a version above 5.0 since on 4.x that the network qos configuration is a Type 1 inconsistency and that can cause your VPC to go down.

HTH

Yamil