Red Hat Enterprise Linux 5 Administration Unleashed

xivRed Hat Enterprise Linux 5 Administration Unleashed22 Monitoring and Tuning Applications 449OProfile ......................................................................................449Setting Up OProfile ...............................................................450Setting Up Events to Monitor .................................................450Starting OProfile ...................................................................453Gathering the Samples ..........................................................453Analyzing the Samples...........................................................453OProfile Review ....................................................................456Using OProfile Graphically .....................................................457Valgrind......................................................................................458Additional Programs to Consider ....................................................460Summary ....................................................................................460Part VI Security 46123 Protecting Against Intruders with Security-Enhanced Linux 463Selecting an SELinux Mode ............................................................464Selecting and Customizing the SELinux Policy ..................................466Utilizing the SELinux Troubleshooting Tool ......................................468Working with Security Contexts......................................................469Viewing Security Contexts .....................................................470Modifying Security Contexts ..................................................470Security Context for Multiple File Sharing Protocols ...................475Making Security Context Changes Permanent ...........................475Summary ....................................................................................47624 Configuring a Firewall 477Selecting a Table and Command for IPTables.....................................478Selecting IPTables Options .............................................................480Using IPTables Match Extensions ....................................................481Using IPTables Target Extensions.....................................................494Starting and Stopping the IPTables Service ........................................500Saving the IPTables Rules ...............................................................501IPTables Examples ........................................................................501Enabling the Default Firewall .........................................................502Summary ....................................................................................50425 Linux Auditing System 505Configuring the Audit Daemon ......................................................505Writing Audit Rules and Watches ....................................................509Writing Audit Rules...............................................................510Writing Audit Watches ..........................................................514Customizing auditctl .............................................................515