Linux: kernel.warning events not logged

The logfile of my firewall was > 1GB so I archived it and echo'd ( echo > firewall.log ) a new one.
After the cleanup no messages where logged to the new firewall.log file, strange because nothing changed in the configuration.

Linux: Install AIDE on RedHat

AIDE is widely used to verify the integrity of the system/configuration files.

What AIDE basically does is take a "snapshot" of the state of the system, register hashes,
modification times and other data regarding the files defined by the administrator.
This "snapshot" is used to build a database that is saved and (usually) stored in an external
device.

In this article I will describe how to configure and use AIDE on a RedHat system....

Linux : Let user's see each others cron jobs

The possibility to look in an other users crontab is only priveleged to the root user. As the root user this can be done with the command crontab -l -u <username>. When multiple users working on the same system it could be desirable to see what cron jobs other users added to the system....

SSH Public Key authentication

In an earlier article I described how to secure your SSH server and ended the artice with the promise to describe how to setup SSH Public key authentication.

Secure SSH on Centos/RedHat 6

Anyone who uses Linux and needs to manage servers or workstations will use SSH.
In this article I will describe how I limit and secure SSH access to my RedHat/CentOS Linux servers.