Now that all objects are ready and heartbeat is configured on the machines, we can move on and build some firewall rules. Since this is a cluster configuration, all rules go into the rule set objects that belong to the cluster rather than its member firewalls.
You can use nmap tool for this job. It is flexible in specifying targets. User can scan entire network or selected host or single server. Nmap is also useful to test your firewall rules. namp is metwork exploration tool and security / port scanner. According to nmap man page: It is an open source tool [...]
You would like to block outgoing access to particular remote host/ip or port for all or selected service/port. In this quick tutorial I will explain how to use iptables to block outgoing access.