[root@esxi:~] tcpdump-uw -i vmk0 -s 1514 port 902 -vv check all the ports (specifically 92 and 443) are enabled on the firewall as TCP and UDP connection in both directions and check from the network side if it is changing the packet header. Get the output for the below command lines. From ESXi: nc -z vCenterIP:902 nc -z vCenterIP:443 From vCenter: curl -v telnet://Host_IP 902 curl -v telnet://Host_IP 443 On ESXi, Packet Capture: pktcap-uw --uplink vmnic0 --capture UplinkSndKernel -o - | tcpdump-uw -r - -nn port 902