Default port permission settings

The default configuration for High security blocks all inbound and outbound traffic through ports not being used by programs you have given access or server permission except:

DHCP broadcast/multicast


Outgoing DHCP (port 67) - on Windows 9x systems


Outgoing DNS (port 53) - If the computer is configured as an ICS gateway
Default access permissions for incoming and outgoing traffic types
Traffic Type	Security levels
	HIGH	MED	LOW
DNS outgoing	block	n/a	allow
DHCP outgoing	block	n/a	allow
broadcast/multicast	allow	allow	allow
ICMP
incoming (ping echo)	block	allow	allow
incoming (other)	block	allow	allow
outgoing (ping echo)	block	allow	allow
outgoing (other)	block	allow	allow
IGMP
incoming	block	allow	allow
outgoing	block	allow	allow
NetBIOS
incoming	n/a	block	allow
outgoing	n/a	allow	allow
UDP (ports not in use by a permitted program)
incoming	block	allow	allow
outgoing	block	allow	allow
TCP (ports not in use by a permitted program)
incoming	block	allow	allow
outgoing	block	allow	allow

To change a port's access permission:

Select Firewall|Main.


In either the Internet Zone Security or the Trusted Zone Security area, click Custom.



The Custom Firewall Settings dialog appears.

Scroll to locate High and Medium security settings.


To block or to allow a specific port or protocol, click the check box beside it.
Be aware that when you select a traffic type in the High security settings list, you are choosing to ALLOW that traffic type to enter your computer under High security, thus decreasing the protection of the HIGH security level. Conversely, when you select a traffic type in the Medium security settings list, you are choosing to BLOCK that traffic type under Medium security, thus increasing the protection of the MED security level.



Click Apply, then click OK.