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Unhide is a little handy forensic tool to find hidden processes and TCP/UDP ports by rootkits / LKMs or by another hidden technique. This tool works under Linux, Unix-like system, and MS-Windows operating systems. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to find hidden processes and ports on Linux/Unix/Windows appeared first on nixCraft. 2024-05-07T05:05:51Z 2024-05-07T05:05:51Z Vivek Gite

Do you need to open a TCP port 43 for outgoing whois command for communication using iptables command? Fear not. You can add a rule to allow incoming or outgoing traffic on that specific port. Here's an example of how to do it. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to open a TCP port 43 for whois command using iptables appeared first on nixCraft. 2023-07-17T20:11:55Z 2023-07-17T20:11:55Z Vivek Gite

Bash is a command language interpreter compatible with sh. It can execute commands read from a file or keyboard. On Debian Linux, bash-completion is a set of shell functions that uses Bash's programmable completion feature. This page provides instructions on installing and enabling Bash auto-completion on Debian Linux versions 10, 11, and 12 to increase productivity by writing custom bash code. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to add bash auto completion in Debian Linux appeared first on nixCraft. 2024-05-06T15:51:25Z 2024-05-06T15:51:25Z Vivek Gite

Recently, I had a learning experience with cron jobs and acme.sh. acme.sh is an excellent tool that simplifies the management of Let's Encrypt TLS (SSL) certificates. It makes obtaining and renewing these essential security certificates for your web server easier. Recently, I moved my server from Linode to AWS, which was a new environment for me. Initially, everything appeared to be working correctly, and I assumed everything was running smoothly. However, I forgot to migrate the cron job that acme.sh uses to renew the certificate automatically. This oversight caused my Let's Encrypt certificates to expire, resulting in security warnings and potential disruptions for visitors to my website. Opps! Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to add cron job entry for acme.sh appeared first on nixCraft. 2024-05-03T06:43:12Z 2024-05-03T06:43:12Z Vivek Gite

{nixCraft Patreon supporters content}Below is a sneak peek of this content! Ubuntu 24.04 LTS (Noble Numbat) was launched on April 25th, 2024. This new version will be supported for five years until June 2029. The armhf architecture now provides support for the Year 2038 problem. The upgrades include significant updates to core packages like Linux kernel, systemd, Netplan, […]The post How to Upgrade Ubuntu 22.04 to 24.04 LTS: A Complete Guide appeared first on Opensource Flare✨. 2024-04-26T18:25:08Z 2024-04-26T18:25:08Z Vivek Gite

Ubuntu 24.04 LTS (Noble Numbat) was launched on April 25th, 2024. This new version will be supported for five years until June 2029. The armhf architecture now provides support for the Year 2038 problem. The upgrades include significant updates to core packages like Linux kernel, systemd, Netplan, toolchain upgrades for better development support, enhanced security measures, and performance optimizations. It also has an updated GNOME desktop environment and other default applications. Let us see how to upgrade Ubuntu 22.04 LTS to Ubuntu 24.04 LTS using the CLI over ssh-based session. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to Upgrade Ubuntu 22.04 to 24.04 LTS: A Complete Guide appeared first on nixCraft. 2024-04-26T08:33:21Z 2024-04-26T08:33:21Z Vivek Gite

AWS SES (Amazon Simple Email Service) is a cloud-based email-sending service that is both reliable and cost-effective. This service is offered by Amazon Web Services. Postfix is a popular email server for Debian and Unix-like systems. It is an open-source Mail Transfer Agent (MTA) responsible for routing and delivering emails. Debian Linux is a widely used Linux distribution known for its stability and user-friendliness for server usage. Let us see how to integrate AWS SES with the Postfix MTA on Debian Linux version 11/12. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to configure AWS SES with Postfix MTA on Debian Linux appeared first on nixCraft. 2024-04-19T07:04:06Z 2024-04-19T07:04:06Z Vivek Gite

When you run the sudo apt update, you may see the following message or error on a Debian Linux: Err:5 http://deb.debian.org/debian buster-backports Release 404 Not Found [IP: 146.75.34.132 80] Reading package lists... Done E: The repository 'http://deb.debian.org/debian buster-backports Release' no longer has a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. Here is how to fix this issue. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post The repository ‘http://deb.debian.org/debian buster-backports Release’ no longer has a Release file. appeared first on nixCraft. 2024-04-14T20:42:01Z 2024-04-14T20:42:01Z Vivek Gite

You can find the timezone in Linux using the command line. The easiest way to do this is to type the "timedatectl" command and look for the "timezone" line when using modern Linux distros with systemd. There are other commands and ways to temporarily switch to a new timezone for date calculations. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How do I find out my timezone in Linux? appeared first on nixCraft. 2024-04-06T01:06:44Z 2024-04-06T01:06:44Z Vivek Gite

The debsecan command is an essential tool for developers and sysadmins using Debian or Ubuntu Linux. It analyzes the list of installed packages on the current host and reports any vulnerabilities found on the system. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to use debsecan command in Linux with examples appeared first on nixCraft. 2024-03-20T05:52:13Z 2024-03-20T05:52:13Z Vivek Gite

When you download Debian Linux CD or DVD images, you must verify the authenticity of Debian Linux CD or DVD images using the gpg and sha512sum command. There are three files you will find here for Debian 12 AMD64 Architecture (download those files using the wget command or use the curl command to download file): $ wget https://cdimage.debian.org/debian-cd/current/amd64/iso-dvd/debian-12.5.0-amd64-DVD-1.iso \ https://cdimage.debian.org/debian-cd/current/amd64/iso-dvd/SHA512SUMS \ https://cdimage.debian.org/debian-cd/current/amd64/iso-dvd/SHA512SUMS.sign Now you have three files as follows: debian-12.5.0-amd64-DVD-1.iso : DVD file for USB or DVD. SHA512SUMS : Checksum file for debian-12.5.0-amd64-DVD-1.iso to ensure that debian-12.5.0-amd64-DVD-1.iso file is not corrupted or contains bad stuff like backdoor. SHA512SUMS.sign : GPG signature file for SHA512SUMS file, which ensures that the checksums file themselves are correct. You must put all these three files into the same directory for easy understanding and verification in a zippy. Use the ls command to list them: {vivek@desktop:~}$ ls -l Outputs: -rw-rw-r-- 1 vivek vivek 3992977408 Feb 10 19:17 debian-12.5.0-amd64-DVD-1.iso -rw-rw-r-- 1 vivek vivek 3372 Feb 10 22:11 SHA512SUMS -rw-rw-r-- 1 vivek vivek 833 Feb 11 01:43 SHA512SUMS.sign Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to verify Debian CD or DVD image using GPG appeared first on nixCraft. 2024-03-07T11:57:43Z 2024-03-07T11:57:43Z Vivek Gite

Btrfs, which stands for "Butter FS" or "B-tree FS," is a modern Linux file system. It was developed to overcome the limitations of older file systems like ext4 or ext3. Btrfs is an excellent choice for efficient storage management on multiple Hard Disk Drivers. It supports Linux file systems with snapshots, subvolumes, and built-in RAID-like capabilities that provide robust data protection. It is designed to handle huge file systems and file sizes. Btrfs incorporates checksumming and COW (Copy-on-write), making it more resilient to data corruption. The COW feature means changes are written to new locations instead of overwriting existing data, enhancing data protection and enabling snapshots. After installation, let us see how to install Btrfs support for Debian Linux 11 or 12 using the CLI. Why am I using BTRFS on an existing Debian Linux system? In my case, the EC2 VM AMI is configured to use ext4 by default at AWS. However, I had to make changes since I needed to store files using EBS (Elastic Block Store) and Python code expected to see BTRFS. Hence, this quick tutorial. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to install BTRFS on a Debian Linux 12/11 appeared first on nixCraft. 2024-02-14T06:10:00Z 2024-02-14T06:10:00Z Vivek Gite

GnuPG2 (or GPG2) is an open-source and free tool that implements the OpenPGP standard. Its primary purpose is to encrypt your sensitive information to protect it from unauthorized access. It also allows you to create digital signatures, guaranteeing that the data hasn't been tampered with while in transit. Many newly created Debian 11/12 cloud VMs and images may not have the gpg/gpg2 command installed. Thus, you will get an error that reads "-bash: gpg: command not found." Here is how to fix this error and install gnupg2 on a Debian Linux 11 or 12. Further, you will learn how to use the gpg command. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to install GPG (gnupg2) on a Debian Linux to fix gpg command not found error appeared first on nixCraft. 2024-02-13T09:38:54Z 2024-02-13T09:38:54Z Vivek Gite

Sometimes, when you try to install specific Debian Linux packages, you might encounter an error message that reads: Unable to locate package pkg-name-here In many cases, the required package might already be present in the remote download repos. It would be best to have an additional repository, such as contrib, which adds extra packages to the core Debian Linux system. To enable and use the contrib repository in Debian Linux version 10/11/12 or newer versions, follow the instructions below. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to enable contrib repo on Debian Linux 10/11/12 appeared first on nixCraft. 2023-12-24T09:18:39Z 2023-12-24T09:18:39Z Vivek Gite

{Updated} Are you getting, ' WARNING: UNPROTECTED PRIVATE KEY FILE!' when try to use the ssh command under Linux, macOS or BSD? Let us see how I fixed this problem and log in using the ssh command.The post SSH WARNING: UNPROTECTED PRIVATE KEY FILE! Error and Solution appeared first on nixCraft. 2023-11-17T10:31:00Z 2023-11-17T10:31:00Z Vivek Gite

The Uncomplicated Firewall (UFW) needs to be configured to allow traffic on UDP ports 67 and 68, regardless of whether the Dynamic Host Configuration Protocol (DHCP) server is local or remote. Additionally, it may be necessary to open both TCP and UDP port 53, which are used for Domain Name Service (DNS). In small business and home environments, typically, both DNS and DHCP services come from a single device. Hence, it would be best if you opened both DHCP and DNS ports using the ufw command. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to open DHCP port using UFW in Linux appeared first on nixCraft. 2023-10-25T10:52:11Z 2023-10-25T10:52:11Z Vivek Gite

I recently had to submit multiple PDF files for government work, but the web form only allowed for the uploading of a single file. This meant that I had to merge the PDF files into one on Linux. To do this, I used a command-line tool called pdfunite, which is a Portable Document Format (PDF) page merger. Let us see how to install and use the pdfunite in Linux. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to merge all PDF files into one PDF in Linux appeared first on nixCraft. 2023-10-24T20:31:44Z 2023-10-24T20:31:44Z Vivek Gite

If you’re using RHEL, CentOS, Rocky, Fedora, or Alma Linux, you may encounter situations where you must list files in a package before installing it. Similarly, there might be instances where you need to locate a specific configuration file after installing the package. In this guide, I’ll provide a quick tip for developers and sysadmins […] Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to list package files with dnf in Linux (RHEL, CentOS, Rocky, Fedora, and Alma Linux) appeared first on nixCraft. 2023-10-23T11:03:32Z 2023-10-23T11:03:32Z Vivek Gite

I am migrating an old Perl project from an unsupported OS to Fedora Linux 38. However, I discovered that Perl is not installed by default, while Python 3 is. This seems ridiculous. Anyway, here is how to install Perl in Fedora Linux including latest version of mod_perl with Apache (HTTPD) and get on with your life. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to install Perl in Fedora Linux appeared first on nixCraft. 2023-10-22T16:25:26Z 2023-10-22T16:25:26Z Vivek Gite

When you try to use the xclip command over the ssh-based session to copy and paste data, you will get the following message on screen: Error: Can't open display: (null) Here is how to fix this error by editing the ssh client and OpenSSH (SSHD server) configuration file. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to fix “Error: Can’t open display: (null)” with ssh and xclip command in headless mode appeared first on nixCraft. 2023-10-08T20:01:52Z 2023-10-08T20:01:52Z Vivek Gite