I just installed a fresh VMware ESXi 5.5 and configured the firewall using vSphere client to not allow remote connections. When testing the firewall I noticed that the rules weren’t working. There seems to be no way to see the status of the firewall or enable/disable it through vSphere but it turned out to be disabled by default.
To enable the firewall, log in to SSH and type this command:
esxcli network firewall set --enabled true