Posts

In the previous post, we described how to install Fail2ban to protect your system. Now we are going to go a step further to activate the reporting of malicious activity to global blacklist managed by the tool AbuseIPDB. What is AbuseIPDB? AbuseIPDB is a project dedicated to helping systems administrators and webmasters check and report IP addresses which are involved in malicious activities such as spamming, hacking attempts, DDoS attacks, or any abusive activity on the Internet....

What is Fail2ban? Fail2ban is a software written in Python which help us to prevent brute force or DDoS attacks. It uses the failed access attempts logged in the system to detect the malicious IP addresses. Then, these IP addresses are blocked to avoid more attempts. It’s a software highly recommended to have installed in any system exposed to The Internet. How does Fail2ban work? Fail2ban is as a daemon which is monitoring every access to the system to the different services which have open ports (Mainly SSH, HTTPS…)....

It’s quite useful to have at your fingertips the option of getting your public IP address. Here I will give you various commands to get the IP. Note not all of them have IPv6 service, so only works with IPv4. IPv4 & IPv6 If you have a connection to the Internet with IPv6, by default, it will be used this interface. However you could force the IPv4 use just adding the -4 option to the curl command....

Introduction In some circunstances it’s not easy to know the commands which exist to compress or decompress files in Linux (and Unix) environments. In this posts, I have wrote all the commands I have used for this. File Types TAR files Pack: tar -cvf file.tar file1 file2 file3 Unpack: tar -xvf file.tar See content: tar -tf file.tar GZ files Compress: gzip -9 file Decompress: gzip -d file BZ2 files Compress: bzip2 file Decompress: bzip -d file....

Grafana is an open source metric analytics & visualization tool which can help us to monitor the system with a nice Dashboard. Installing Grafana Grafana is available in the APT packages repository, however it could not be the latest version, so we’ll use the official Grafana repository. First, it is needed to install the software needed before install Grafana. sudo apt install -y apt-transport-https sudo apt install -y software-properties-common wget Next step is to download the GPG Key, in order to install signed packages:...

Introduction Some time ago I tried to configure a SMTP server in a host in the cloud, but because of some restrictions, the emails from that server were bounced. The problem was that the hosting provider didn’t configure the PTR DNS entries (more about DNS PTR entries) for some kind of hostings. When this happens the best solution is to use a SMTP relay server, by this way that server is in charge of the final delivery of the emails....

First off, as a prerequisite it is needed to have a CLI access to the Debian OS. It can be done using a keyboard and a screen connected to the Raspberry Pi, or using a SSH connection. If you have followed the post of how to install Debian On a Raspberry Pi 4, you should be able to access with SSH using the Ethernet (RJ45) port. Also, you should have the SSID and the password of your Wi-Fi connection, and it should be enabled the DHCP protocol in your router....

I have several Raspberry Pi and in all of them I have used the Ubuntu distro. However I also wanted to use Debian as it is one of the most used Linux distros. Besides Ubuntu is based on Debian, so I guess I will feel confortable with it. Debian vs Ubuntu Debian is more stable than Ubuntu, indeed, it is one of the most stable Linux. The releases in Debian are not as frequent as in Ubuntu, and the software updates in Debian usually don’t have the latest versions....