Jumbo Frames (MTU 9000) test between ESXi hosts

You must have Jumbo-Fames enabled on physical switches, in VMware Distributed Switch, and on all VMkernel interfaces where you would like to use Jumbo-Frames.

You can test Jambo-Frames (large MTU size) by pinging between two ESXi hosts. 

ESX11 has IP address 10.160.22.111 on vMotion vmk interface within vMotion TCP/IP stack. 

ESX12 has IP address 10.160.22.112 on vMotion vmk interface within vMotion TCP/IP stack.

[root@esx11:~] ping -I vmk1 -S vmotion -s 8972 -d 10.160.22.112
PING 10.160.22.112 (10.160.22.112): 8972 data bytes
8980 bytes from 10.160.22.112: icmp_seq=0 ttl=64 time=0.770 ms
8980 bytes from 10.160.22.112: icmp_seq=1 ttl=64 time=0.637 ms
8980 bytes from 10.160.22.112: icmp_seq=2 ttl=64 time=0.719 ms

Above is succesful test of large ICMP packets with flag -d (fragmentation disabled). Packets with size 8972 bytes can be transfered over the network without fragmentation. 

Bellow is visible that packets with size 8973 bytes cannot be transfered over the network without fragmentation.

[root@esx11:~] ping -I vmk1 -S vmotion -s 8973 -d 10.160.22.112
PING 10.160.22.112 (10.160.22.112): 8973 data bytes
sendto() failed (Message too long)
sendto() failed (Message too long)
sendto() failed (Message too long)

This is how network with Jumbo Frames enabled should behave.