Configuring Manually - Novell LINUX ENTERPRISE SERVER 10 SP2 - INSTALLATION AND ADMINISTRATION Installation Manual

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
Only 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.
All services, ports, and protocols that have been allowed are listed in this summary. To
modify the configuration, use Back. Press Accept to save your configuration.

43.4.2 Configuring Manually

The following paragraphs provide step-by-step instructions for a successful configura-
tion. Each configuration item is marked as to whether it is relevant to firewalling or
masquerading. Use port range (e.g., 500:510) whenever appropriate. Aspects related
to the DMZ (demilitarized zone) as mentioned in the configuration file are not covered
here. They are applicable only to a more complex network infrastructure found in
larger organizations (corporate networks), which require extensive configuration and
in-depth knowledge about the subject.
First, use the YaST module System Services (Runlevel) to enable SuSEfirewall2 in
your runlevel (3 or 5 most likely). It sets the symlinks for the SuSEfirewall2_* scripts
in the /etc/init.d/rc?.d/ directories.
FW_DEV_EXT (firewall, masquerading)
The device linked to the Internet. For a modem connection, enter ppp0. For an
ISDN link, use ippp0. DSL connections use dsl0. Specify auto to use the in-
terface that corresponds to the default route.
Masquerading and Firewalls 831