Tankyou msripada !

ESXi host disconnect immediately (msx 5-10 sec, not 60, not 120 sec)  after clicking PowerOn button.

I have several  ESXi server, but problem only at one - 172.16.37.179.

172.16.37.179   ESXi 6.5  disconnect  when VM Power UP.

172.16.37.100  ESXi 5.5   work fine

172.16.37.127  ESXi 5.5   work fine

172.16.37.177  ESXi 5.5  work fine

172.16.37.179   ESXi 6.5 work fine

172.16.37.210   ESXi 6.5 work fine

172.16.37.209    vCenter 6.5

Result  nmap -sU -sV -p 904 -PU 172.16.37.XXX :

172.16.37.179   ESXi 6.5  disconnect 

PORT    STATE  SERVICE

904/udp open|filtered unknown

172.16.37.100  ESXi 5.5   work fine

PORT    STATE  SERVICE

904/udp closed unknown

172.16.37.127  ESXi 5.5   work fine

PORT    STATE         SERVICE

904/udp open|filtered unknown

172.16.37.177  ESXi 5.5  work fine

PORT    STATE  SERVICE

904/udp closed unknown

172.16.37.210   ESXi 6.5 work fine

PORT    STATE         SERVICE

904/udp open|filtered unknown

172.16.37.209    vCenter 6.5

PORT    STATE         SERVICE

904/udp open|filtered unknown