As a part of a network hardware refresh project, all the network switches have been replaced with a newer, high-performance model. After the replacement, the company users started experiencing slowness on the applications hosted on their vSAN-backed VMs.
The vSAN administrator checked the vSAN Network Health status and noticed that the "Hosts large ping test" has failed.
What could be the cause of this performance degradation issue?
The performance degradation issue is likely due to the MTU 9K not being configured on the ToR (Top of Rack) switch. If the new high-performance network switches are not set to support Jumbo Frames (MTU 9000), the large ping test for the vSAN Network Health will fail because the switches will enforce a smaller MTU size, typically 1500. This mismatch can lead to fragmentation and performance issues, which could explain the slowness experienced by the company users after the hardware refresh.
My answer is C
C. Large ping test will fail if the switch is enforcing 1500 instead of 9000 MTU. https://kb.vmware.com/s/article/2108285