Excluded hosts are supported for network intrusion prevention only.
You can set up a list of computers for which the client does not match attack signatures or check for port scans or denial-of-service attacks. Network intrusion prevention and peer-to-peer authentication allow any source traffic from hosts in the excluded hosts list. However, network intrusion prevention and peer-to-peer authentication continue to evaluate any destination traffic to hosts in the list. The list applies to both inbound traffic and outbound traffic, but only to the source of the traffic. The list also applies only to remote IP addresses.
For example, you might exclude computers to allow an Internet service provider to scan the ports in your network to ensure compliance with their service agreements. Or, you might have some computers in your internal network that you want to set up for testing purposes.
You can also set up a list of computers that allows all inbound traffic and outbound traffic unless an IPS signature detects an attack. In this case, you create a firewall rule that allows all hosts.
To set up a list of excluded computers
In the console, open an Intrusion Prevention policy.
On the policy page, click Intrusion Prevention.
If not checked already, check Enable excluded hosts and then click Excluded Hosts.
In the Excluded Hosts dialog box, check Enabled next to any host group that you want to exclude from network intrusion prevention.