Security, Optimization and Upgrade


Table of Contents

5. General System Security
BIOS
Security as a Policy
Choose a right Password
The root account
The /etc/exports file
Disable console program access
Disable all console access
The inetd - /etc/inetd.conf file
TCP_WRAPPERS
Don't display system issue file
The /etc/host.conf file
The /etc/services file
The /etc/securetty file
Special accounts
Blocking; su to root, by one and sundry
Put limits on resource
Control mounting a file system
Conceal binary RPM
Shell logging
The LILO and lilo.conf file
Disable Ctrl-Alt-Delete keyboard shutdown command
Physical hard copies of all-important logs
Tighten scripts under /etc/rc.d/
The /etc/rc.d/rc.local file
Bits from root-owned programs
The kernel tunable parameters
Prevent your system responding to Ping
Refuse responding to broadcasts request
Routing Protocols
Enable TCP SYN Cookie Protection
Disable ICMP Redirect Acceptance
Enable always-defragging Protection
Enable bad error message Protection
Enable IP spoofing protection
Log Spoofed, Source Routed and Redirect Packets
Unusual or hidden files
System is compromised !
6. Linux General Optimization
The /etc/profile file
Benchmark Results
Benchmark results-i586
Benchmark results -i486
The bdflush parameters
The buffermem parameters
The ip_local_port_range parameters
The /etc/nsswitch.conf file
The file-max parameter
The ulimit parameter
The atime and noatime attribute
Tuning IDE Hard Disk Performance
Better manage your TCP/IP resources
7. Configuring and Building a Secure, Optimized Kernel
Pre-Install
Make an emergency boot floppy
Uninstallation and Optimization
Securing the kernel
Compilation
Kernel configuration -Part "A"
Kernel configuration -Part "B"
Kernel configuration -Part "C"
Kernel configuration -Part "D"
Kernel configuration -Part "E"
Installing the new kernel
Delete programs, Edit files pertaining to modules
Create a emergency Rescue and Boot floppy disk
Bat

Abstract

Now that we have installed a base system, the next three chapters will concentrate on

  • How to tighten the security of our configured system.

  • Optimise our sytem to perform at its peak.

  • Upgrade our machine for the latest kernel.

Please note when we talk of tightening the security we are referring to the features available within the base installed system and not to any new additional software. We will talk about that later in this book.