May 2020 02
Collecting diagnostic data over SSH
Posted By : cybergavin

A couple of months ago, I had a requirement to gather diagnostic data from Palo Alto Networks (PAN) firewalls every few seconds for the PAN support technicians to assist us with identifying the root cause

May 2020 02
Customized Fail2Ban for SFTP Protection
Posted By : cybergavin

Fail2Ban is an intrusion-prevention software that scans log files and takes action as directed. Hence, it may be used to scan SSH logs for invalid user attempts or authentication failures and invoke iptables to block

May 2020 02
Large character printing using FIGlet
Posted By : cybergavin

FIGlet (Frank, Ian and Glenn’s letters) is a handy program that makes large characters from small characters provided as input. This is useful for banners (as a matter of fact, the program was first called

September 2012 06
Sendmail is slow
Posted By : cybergavin

Problem: The sendmail service takes a while (more than a minute) to start and emails sent via sendmail take a couple of minutes to get delivered:   Background & Analysis: Sendmail uses DNS for the

January 2012 15
How to Install PHP with FreeTDS on Linux
Posted By : cybergavin

There are PHP applications which use MSSQL as the back-end database and such applications require FreeTDS to enable PHP code interface with MSSQL. This article describes how to install PHP and FreeTDS on Linux hosts.

December 2011 09
How to install Tomcat 6 on RHEL 6
Posted By : cybergavin

Installing software on RHEL platforms using yum is straightforward. However, based on your environment, there could be a few more steps to get there. So, here’s what I did to install Tomcat 6 on RHEL

October 2011 05
How PAM works
Posted By : cybergavin

Pluggable Authentication Modules (PAM) is a framework used for authentication. Typically, most Linux distros come with PAM installed by default. PAM can be powerful if used well and it’s important to understand how PAM works.

September 2011 27
Cannot connect to MySQL on a remote host
Posted By : cybergavin

Problem: Cannot connect to a MySQL database on a remote host (port 3306) Firewalls aren’t blocking traffic and network connectivity is available. The MySQL database is up and running on the remote host and can

September 2011 22
How to build AMP from source on RHEL 5.7
Posted By : cybergavin

Typically, building a LAMP system on RHEL may be performed by yum installs. However, I wanted specific options built-in for my AMP and I wanted to locate the software in specific locations. hence, I opted

July 2011 26
How to create a CSR using openssl
Posted By : cybergavin

A CSR or Certificate Signing Request is an encrypted block of text that is used to request a digital certificate from a Certificate Authority (CA). A key pair (public/private keys) must be created before or

May 2011 08
Automate Requests for New Certificates
Posted By : cybergavin

Recently, all Windows XP workstation users within a corporate domain were required to request and install a certificate from the Enterprise Certificate Authority (Active Directory Certificate Services). Typically, the Certificate Manager Management console Snap-in Control