Block everything except

How can I block any IP in/out connection except for those to some particular hosts (or ip addresses)?

The Network Security Policy interface is the nerve center of Comodo Firewall and allows you to configure and deploy traffic filtering rules and policies on an application specific and global basis.

  1. Open Comodo Personal Firewall
  2. Under Firewall Tasks in the left pane, clik on Advanced
  3. Click on Network Security Policy
  4. Click on Global Rules tab
  5. Add a rule specifying the following settings

Action : Define the action the firewall will take when the conditions of the rule are met. Options available via the drop down menu are ‘Allow’, ‘Block’ or ‘Ask’.

Protocol: Allows you to specify which protocol the data packet should be using. Options available via the drop down menu are ‘TCP’, ‘UDP’, ‘TCP or UDP’, ‘ICMP’ or ‘IP’ (note: your choice here alters the choices available to you in the tab structure on the lower half of the interface)

Direction: Allows you to define which direction the packets should be traveling. Options available via the drop down menu are ‘In’, ‘Out’ or ‘In/Out’

Log as a firewall event if this rule is fired: Checking this option will create a entry in the firewall event log viewer whenever this rule is called into operation. (i.e. when ALL conditions have been met).

Description: Allows you to type a friendly name for the rule. Some users find it more intuitive to name a rule by it’s intended purpose. ( ‘Allow Outgoing HTTP requests’). If you create a friendly name, then this will be displayed to represent instead of the full actions/conditions in the main Application Rules Interface and the Application Network Access Control interface.

TCP’, ‘UPD’ or ‘TCP or UDP’

If you select ‘TCP’, ‘UPD’ or ‘TCP or UDP’ as the Protocol for your network, then you will have to define the source and destination IP addresses and ports receiving and sending the information.