Novell LINUX ENTERPRISE SERVER 10 - INSTALLATION AND ADMINISTRATION 11-05-2007 Installation Manual page 841

Interfaces
All known network interfaces are listed here. To remove an interface from a zone,
select the interface, press Change, and choose No Zone Assigned. To add an interface
to a zone, select the interface, press Change and choose any of the available zones.
You may also create a special interface with your own settings by using Custom.
Allowed Services
You need this option to offer services from your system to a zone from which it is
protected. By default, the system is only protected from external zones. Explicitly
allow the services that should be available to external hosts. Activate the services
after selecting the desired zone in Allowed Services for Selected Zone.
Masquerading
Masquerading hides your internal network from external networks, such as the In-
ternet, while enabling hosts in the internal network to access the external network
transparently. Requests from the external network to the internal one are blocked
and requests from the internal network seem to be issued by the masquerading
server when seen externally. If special services of an internal machine need to be
available to the external network, add special redirect rules for the service.
Broadcast
In this dialog, configure the UDP ports that allow broadcasts. Add the required
port numbers or services to the appropriate zone, separated by spaces. See also the
file /etc/services.
The logging of broadcasts that are not accepted can be enabled here. This may be
problematic, because Windows hosts use broadcasts to know about each other and
so generate many packets that are not accepted.
IPsec Support
Configure whether the IPsec service should be available to the external network in
this dialog. Configure which packets are trusted under Details.
Logging Level
There are two rules for the logging: accepted and not accepted packets. Packets
that are not accepted are DROPPED or REJECTED. Select from Log All, Log
Critical, or Do Not Log Any for both of them.
When completed with the firewall configuration, exit this dialog with Next. A zone-
oriented summary of your firewall configuration then opens. In it, check all settings.
Masquerading and Firewalls 823