III. Network Services Reference .................................................................................................... 157

12. Network Scripts .............................................................................................................. 159

12.1. Network Configuration Files............................................................................ 159

12.2. Interface Configuration Files ........................................................................... 159

12.3. Interface Control Scripts .................................................................................. 163

12.4. Network Functions........................................................................................... 164

12.5. Additional Resources ....................................................................................... 165

13. Firewalls and

iptables

................................................................................................. 167

13.1. Packet Filtering ................................................................................................ 167

13.2. Differences between

iptables

and

ipchains

............................................. 168

13.3. Options Used in

iptables

Commands .......................................................... 169

13.4. Storing

iptables

Information ....................................................................... 175

13.5. Additional Resources ....................................................................................... 176

14. Apache HTTP Server ...................................................................................................... 177

14.1. Apache HTTP Server 2.0 ................................................................................. 177

14.2. Migrating Apache HTTP Server 1.3 Configuration Files ................................ 178

14.3. After Installation .............................................................................................. 187

14.4. Starting and Stopping

httpd

........................................................................... 188

14.5. Configuration Directives in

httpd.conf

....................................................... 189

14.6. Default Modules............................................................................................... 204

14.7. Adding Modules to Your Server ...................................................................... 205

14.8. Using Virtual Hosts.......................................................................................... 206

14.9. Additional Resources ....................................................................................... 208

15. Email ............................................................................................................................... 209

15.1. Protocols .......................................................................................................... 209

15.2. Email Program Classifications......................................................................... 211

15.3. Sendmail .......................................................................................................... 212

15.4. Fetchmail.......................................................................................................... 216

15.5. Procmail ........................................................................................................... 220

15.6. Security ............................................................................................................ 225

15.7. Additional Resources ....................................................................................... 226

16. Berkeley Internet Name Domain (BIND)....................................................................... 229

16.1. Introduction to DNS and BIND ....................................................................... 229

16.2. BIND Configuration Files................................................................................ 230

16.3. Using

rndc

...................................................................................................... 240

16.4. Advanced Features of BIND............................................................................ 242

16.5. Common Mistakes to Avoid ............................................................................ 243

16.6. Additional Resources ....................................................................................... 244

17. Network File System (NFS)............................................................................................ 247

17.1. Methodology .................................................................................................... 247

17.2. NFS Server Configuration Files....................................................................... 249

17.3. NFS Client Configuration Files ....................................................................... 251

17.4. Securing NFS ................................................................................................... 253

17.5. Additional Resources ....................................................................................... 254

18. Lightweight Directory Access Protocol (LDAP)............................................................ 257

18.1. Why Use LDAP? ............................................................................................. 257

18.2. OpenLDAP Daemons and Utilities.................................................................. 258

18.3. LDAP Terminology.......................................................................................... 259

18.4. OpenLDAP Configuration Files....................................................................... 260

18.5. OpenLDAP Setup Overview............................................................................ 262

18.6. Upgrading To OpenLDAP Version 2.0 ............................................................ 263

18.7. Configuring Your System to Authenticate Using OpenLDAP......................... 263

18.8. Additional Resources ....................................................................................... 265