Sentry Firewall CD HOWTO Sentry Firewall CD HOWTO Table of Contents Sentry Firewall CD HOWTO............................................................................................................................1 Stephen A. Zarkos, Obsid@Sentry.net....................................................................................................1 1. Introduction..........................................................................................................................................1 2. How the CD Works (Overview)..........................................................................................................1 3. Obtaining the CDROM........................................................................................................................1 4. Using the Sentry Firewall CDROM.....................................................................................................1 5. Overview of Available Configuration Directives................................................................................1 6. Setting Up a Firewall...........................................................................................................................2 7. Troubleshooting...................................................................................................................................2 8. Building a Custom Sentry CD.............................................................................................................2 9. More About the Sentry Firewall Project..............................................................................................2 1. Introduction..........................................................................................................................................2 1.1 What is the Sentry Firewall CD?.......................................................................................................3 1.2 Why would I use a CD−based firewall or server?.............................................................................3 1.3 I'm a Linux newbie, will the Sentry Firewall CD be a good choice for me?.....................................3 1.4 What's with all these branches(SENTRYCD/SENTRYCD−RH/SENTRYCD−xxx)? What's the difference between the branches?...........................................................................................................3 1.5 Minimum Requirements....................................................................................................................4 1.6 Copyrights and Disclaimer................................................................................................................4 2. How the CD Works (Overview)..........................................................................................................4 2.1 The Boot Process...............................................................................................................................5 2.2 ISOLINUX.........................................................................................................................................5 2.3 The CD Configuration Scripts...........................................................................................................5 3. Obtaining the CDROM........................................................................................................................6 3.1 Downloading......................................................................................................................................6 3.2 Purchasing..........................................................................................................................................6 3.3 Burning the CDROM.........................................................................................................................6 4. Using the Sentry Firewall CDROM.....................................................................................................7 4.1 Introduction........................................................................................................................................7 4.2 The sentry.conf file............................................................................................................................7 Example.............................................................................................................................................7 4.3 Network Configuration......................................................................................................................8 Example.............................................................................................................................................9 4.4 Other Useful Configuration Directives............................................................................................10 4.5 Putting it all together, managing multiple nodes from a single location.........................................10 4.6 Example sentry.conf and disk images..............................................................................................11 5. Overview of Available Configuration Directives..............................................................................11 5.1 Replacing rc/config files..................................................................................................................11 5.2 'device' directive support..................................................................................................................12 5.3 'nameserver' directive.......................................................................................................................12 5.4 Proxy Support Directives.................................................................................................................12 5.5 Passive FTP Support........................................................................................................................13 5.6 'include' directive.............................................................................................................................13 5.7 Copying files (|=).............................................................................................................................13 5.8 Making Symlinks (=>).....................................................................................................................13 5.9 'cdrom' directive...............................................................................................................................14 5.10 'cron' directive................................................................................................................................14 5.11 hostname........................................................................................................................................14 i Sentry Firewall CD HOWTO Table of Contents Sentry Firewall CD HOWTO 5.12 Other SENTRY−{RH,DEB} Specific Directives..........................................................................14 Start/Stop a Service or Daemon......................................................................................................14 6. Setting Up a Firewall.........................................................................................................................15 6.1 Starting the Firewall.........................................................................................................................15 6.2 Using FWBuilder with the Sentry Firewall CD...............................................................................15 6.3 Using Webmin with the Sentry Firewall CD...................................................................................16 6.4 Other Sample Firewall Scripts and Tools........................................................................................16 6.5 Links to Other Firewall Resources..................................................................................................17 7. Troubleshooting.................................................................................................................................17 7.1 Booting Problems............................................................................................................................17 7.2 Configuration Problems...................................................................................................................18 7.3 Frequently Asked Questions............................................................................................................18 7.4 Mailing List......................................................................................................................................18 8. Building a Custom Sentry CD...........................................................................................................18 8.1 Introduction......................................................................................................................................18 8.2 The development system(How I do it).............................................................................................18 8.3 The RAMdisk Image........................................................................................................................20 8.4 Making the ISO Image.....................................................................................................................20 9. More About the Sentry Firewall Project............................................................................................21