Security   Security – Create self signed SAN certificate with OpenSSL

This post explains how to generate self signed certificates with SAN – Subject Alternative Names using openssl. It is a common but not very funny task, only a minute is needed when using this method.

The example below generates a certificate with two SubAltNames: and

Create openssl configuration file

Create configuration file for openssh (In a Linux … Read more

Linux   Linux – TCP listener daemon with tcpserver

To configure passive checks in Nagios/icinga I use a tcp listener daemon that launches a script (See Nagios – Using passive checks without agent)
Tried to use inetd superserver daemon, but in the last versions, i have not been able to make it work correctly (See last update in my post: Linux – cannot found / missing inetd.conf)Read more

Linux   Linux – Create multiboot CD combining multiple ISO images

This post shows the steps to create a multiboot cd with multiple Linux distributions or tools.

For example, I created a recovery / disaster case cd with the following tools:
Clonezilla (to clone/recover disks and partitions)
Gparted (partition editior with GUI)
Trinity Rescue Kit (linux distribution for recovery and repair operations on Windows machines)

The Multicd Read more

F5 BIG-IP icon   F5 BIG-IP – Apply SNAT to client subnet or IP

In certain scenarios it can be interesting or necessary to apply SNAT only to certain client IPs when accesing a virtual server to  f.e. avoid assymetric routes, when the server gateway is not the F5… (take a look at this link for more examples).

These are the steps (im using BIG IP v13)…

Create a SNAT pool

I prefer the … Read more

Raspberry icon   Raspberry – Raspbian installation and initial setup

Some time ago I started reading documentation about Raspberry. Nothing related to my job but, as a hobby/challenge, I decided to buy one and start a project in future posts I will talk about…

Also owner of a Raspberry? Follow this minitutorial to perform the basic installation of Raspbian OS with remote access enabled via SSH using WiFi connection.… Read more

POWERSHELL   Powershell – Excel reports automation (I)

Powershell can be very useful to extract data from our systems.
Excel can be very useful to show that data in a friendly way.
Powershell + Excel = Automatic generation of useful reports

These are the basic powershell sentences and functions needed to start generating our Excel reports using Powershell scripts:

Excel COM object

It is neccesary to reference a … Read more