Hello guys,
I finally found the problem.
The ESXi servers are configured with MTU 9000, but the switch where hosts are connected had a documented bug with Jumbo frames. I found the problem after find this article http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1003734
I execute command from ESXi-1:
vmkping -d -s 8972 192.168.10.12 where 192.168.10.12 is ip address of ESXi-2
The result was:
3 packets transmitted, 0 packets received, 100% packet loss
like workaround I reduce the MTU to 1500, then I patched the problematic switch.