The client is EES with policy-based firewall. By default, the built-in rules allow the agent communication and many other things.
I creating on the ESMC a policy with 2 firewall rules, nothing more or less.
Then I assign to the client the policy, After the next client connection to the ESMC, the clients built-in firewall rules are deleted remaining just the two rules assigned by the ESMC.
Thanks
Levi