You need the S.u.S.E. package firewall which can be installed by using YaST or rpm. It's distrubuted with the S.u.S.E. CDs or you can download it from the S.u.S.E. FTP site.
It contains the following files:
/sbin/init.d/masquerade Setting up masquerading
/sbin/init.d/firewall Setting up the firewall
/sbin/fcii Daemon used for IP redirecting
/etc/fw-ssh List of hosts that have ssh permissions
/etc/fw-friends List of friends
/etc/fw-inout List of hosts that have access
to the Internet
/usr/doc/packages/firewall/* Documentation on the firewall package
Also included are some links that provide starting up everything at boot time.
The current version is 1.4. This ducument refers to this version. Please update your firewall package if you have a version prior to 1.4.