OpenSSH usually listens on TCP port 22. However, there are some people who wish to change OpenSSH port to avoid brute-force bot attacks or to avoid from being blocked by restrictive firewall.

To change OpenSSH port, one only need to edit “/etc/ssh/sshd_config” file and change the port at “Port 22” to something else, like “Port […]

#!/bin/bash if[ $# -lt 1 ] ; then echo “Usage: “ echo ” threads_per_process.sh PID | process name [count] “ echo “” echo “Example” echo ” PID: 36434 or” echo ” process string: NumThreads (this script will do a ps -ef|grep NumThreads to get the PID)” echo ” The last number is the number […]

we need an automatic login from host A / user a to Host B / user b. You don’t want to enter any passwords, because you want to call sshfrom a within a shell script.

How to do it

First log in on A as user a and generate a pair of authentication keys. Do […]

CentOS6.0 no longer uses faillog for keeping track of failed login attempts. Here’s an easy way to get up login tracking, and SSH time outs for PCI compliance, or just for a nice secure system.

Firstly you want to edit /etc/ssh/sshd_config to set up a timeout for SSH. You want to change the following lines;

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Securing SSH

SH is how most administrators connect to their servers. It is also one of the most commonly attacked ports on a Linux Server. If you followed my previous tutorial about how to install fail2ban, you’ve probably noticed that you receive many emails about failed attacks. In this tutorial, I’ll show a few […]