Linux Admin Zone

Some times we need a way to automatically save any user’s or root’s activity so that we can check later. In environment, where root account is accessible by multiple people, its very helpful to exactly know who did what and when? In my case, I have found that some files are changed mysteriously but I was clueless as there are more than one users with root access.

To save the activity/history of any user (including root), you need to open the user’s .bash_profile from his home directory.

Brute force attacks or dictionary based attacks are common these days for servers. DenyHosts is an excellent python tool to prevent such attacks. It will detects failed attempts and prevent offending Host/IP for further connection by adding it to /etc/hosts.deny.

Here are steps to install and configure DenyHosts for your server. These steps are applicable for Red Hat based distros (ie RHEL, CentOS, Fedora) and needs minor changes for other distros. You can copy paste the commands.

Step 1. Detect which version of Python is installed on your server:
# python -V