View source for Linux server security

== Installing intrusion detection ==

In hostile environments such as server environments, using a FIA makes sense only if it is installed, fully configured and initialised at the very first boot after an installation from scratch, before ever connecting to the internet or doing anything else. It takes only one attack to install a backdoor. Installing ''aide'' or ''tripwire'' after such an event would guarantee that the backdoor remains just as open as the day an intruder installed it. For more on ''aide'' vs ''tripwire'', see [[Linux applications#Intrusion detection|Linux applications: Intrusion detection]], and for an example install of aide, see [[Linux_security#Installing_intrusion_detection|Linux security: Installing intrusion detection]].

=== tripwire ===

== Installing 

== Server connections ==

=== Remote commands and procedure calls ===

ssh, rssh, scp and sftp.

Remote Procedure Calls (RPC), Portmapper

=== Network Wrappers (PAM) ===

=== ICMP === 

Blocking ICMP and look invisible to ping.

== Traffic analysis ==

=== snort ===

=== Traffic control ===

Traffic Control (TC) and TC New Generation (TCNG)