In the previous post I explained what is the difference between Icinga active and passive checks, why can be interesting to use passive checks, what is the result format Icinga is expecting when processing those checks and the way I use to send those results (instead of using snmp traps).
Now it is time to show how to configure it … Read more
As I posted long time ago for Nagios (Nagios – Using passive checks without agent), it is time to show an easy way to configure Icinga to perform passive checks (without using SNMP traps).
This is the first of two posts. In this I only want to make some theoretical explanations and then in the second I will … Read more
This time a simple as well as important post. Have you tried to run a scheduled task every minute?
When editing the trigger of a task schedule, there is a section in which the “Repeat task every” parameter can be set, and you have probably noticed that by default only the values “5 minutes, 10 minutes, 15 minutes, 30 … Read more
In a previous post I showed how to upgrade your laptop HDD (Hard Disk Drive) to an SSD (Solid State Drive) to boost up performance. In this post, instead of removing the HDD, it will placed in the DVD bay to be used as a second storage.
Given that the use of ODD (Optical Disk Drive) to read or write … Read more
One of the biggest bottlenecks regarding the performance of a laptop is disk access. Therefore, installing an SSD (Solid State Drive) is a fantastic way to speed it up. It is a great feeling to see how fast Windows or any program starts after installing it. The only disadvantage is the price of this type of disks, but currently, … Read more
Today, just when starting the working day we have realized that there were somes servers offline (still powered on but without network connection). It seemed that the network adapters were incorrectly configured without the static IPs.
After some research, a job partner discovered that some days ago (March 13th) Microsoft released some security updates that generates issues to Windows 2008 … Read more
Step by step procedure to upgrade an active/standby BIGIP cluster. In this example, I needed to upgrade from BIG IP v188.8.131.52 to v184.108.40.206
Login to https://downloads.f5.com/, search and download the ISO image of the version you want to upgrade to.
As a good sysadmin practice, it is better to export the configuration of both nodes … Read more
The last F5 BIGIP version 220.127.116.11 (I upgraded from v13.0.0 some days ago – 2018 February) seems to generate a bug with the LTM policies.
Fortunately, the issue is only at the Presentation layer. The LTM policy show the rules conditions always with datagroups. This affects all rules and policies.
Better explained with an example:
If this is a … Read more
Last week we published a new application on our web servers (which are balanced by the F5 BIGIP)
Accessing directly to the servers produced no problem, but when the connection was through the virtual balancing IP of the F5, the application did not work correctly.
Fortunately, monitoring the LTM module logs of the F5 (/var/log/ltm) while the problem … Read more
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: mydomain.com and www.mydomain.com
Create openssl configuration file
Create configuration file for openssh (In a Linux … Read more