02-03-2022 08:28 AM
Hi,
I have installed one hypeflex cluster 4.0.2 with FI 6454 (Clean Install) and on UCS Manager i noticed that on QoS System Classes all priorities (Platinum,Gold, Silver, Bronze,Best Effort) had MTU set to 9216. In Cisco documentation i saw only MTU set to 92126 on Platinum and Bronze Priority that is used by Storage vnic template and Vmotion vnic template.
Also On vnic Templates only show MTU 9000 in the Storages and Vmotion templates..
Will this cause impact or its just an mistake done by HX Data platform installer?
Another question regarding Jumbo MTU, if i connect this hyperflex cluster to upstream network switches without jumbo frames configured .In normal operation i won't notice impact correct? Only if some node or connection fails and i need to traverse upstream switches correct?
Thanks.
Solved! Go to Solution.
02-13-2022 07:46 AM
Those are default settings for the 6454 (i.e. best effort having 9216 set).
VMware uses 9000 MTU max size, as you want to leave some room for overhead potential (i.e. OTV, vxlan, etc) and don't want your OS level creating frames that completely max out our networking gears capability.
Having QOS classes that 'allow' the 9216 frame size, doesn't make the traffic be jumbo in nature, it just 'allows' for it, and doesn't drop it.
Here is a potential scenario if your upstream networking does not allow jumbo frames, but you have it set/configured at Hyperflex level.
Kirk...
02-13-2022 07:46 AM
Those are default settings for the 6454 (i.e. best effort having 9216 set).
VMware uses 9000 MTU max size, as you want to leave some room for overhead potential (i.e. OTV, vxlan, etc) and don't want your OS level creating frames that completely max out our networking gears capability.
Having QOS classes that 'allow' the 9216 frame size, doesn't make the traffic be jumbo in nature, it just 'allows' for it, and doesn't drop it.
Here is a potential scenario if your upstream networking does not allow jumbo frames, but you have it set/configured at Hyperflex level.
Kirk...
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