I have a home lab setup with a single SG300-20 (firmware 184.108.40.206, L3 mode) connected to a server with 4 NICs running ESXi 6.0. I have a number of virtual machines running ESXi 6.0 (nested ESXi). Because the nested ESXi hosts are connected by a virtual switch on the physical ESXi host normally (unicast) traffic between these virtual machines does not need to go to the physical switch (SG300). This version of vSAN has a requirement for multicast. There is a test built-in to vSAN for multicast that indicates all is not well. I have experimented with different settings on the switch (enabling/disabling IGMP snooping and querier) which changes the results of this test. I have a dedicated VLAN and subnet exclusively for VLAN traffic. The best results seem to be when both IGMP snooping and IGMP querier are both enabled.
One thing I have done on the nested ESXi hosts is add add a static route for the multicast address (220.127.116.11) to the network interface (vmk4) dedicated to vSAN:
This didn't seem to make much of a difference. Having read the section on Multicasting in "Cisco_300Sx_v1_4_AG.pdf" I'm still not sure what, if any, changes I should be making to the SG300. I really don't know multicasting, so I'm kinda stuck.
 vSAN Multicast performance test fails (2135495) https://kb.vmware.com/kb/2135495
... which lead me to section "Multicast performance test of Virtual SAN health check does not run on Virtual SAN network " ...
VMware Virtual SAN 6.1 Release Notes http://pubs.vmware.com/Release_Notes/en/vsan/61/vmware-virtual-san-61-release-notes.html#knownissues