Linux System Administration 
...le the
Magic-SysReq key
Use system-config-proc to disable
ICMP broadcast
Section 3 Post-Install
System Configuration
Configuration
Utilites and Files Network Services Managing System Time and Network-Wide Time Continual Time Sync - NTP Configuring NTP Clients Managing Software RPM Features, Architecture, and Package Files Working With RPMs Querying and Verifying with RPM Package
more...