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Tag: linux

A Comprehensive Guide to Securing SSH on Ubuntu 22.04

Published July 23, 2023

SSH (Secure Shell) is a widely used protocol for securely accessing remote servers. However, its popularity also makes it a target for potential attackers. To ensure the safety of your Ubuntu 22.04 server, it is crucial to implement robust security measures for SSH. In this article, we will discuss essential steps to secure SSH on Ubuntu 22.04, safeguarding your server from unauthorized access and potential security breaches. Locate the line containing PermitRootLogin and set it to no: Save the file…

(More…)A Comprehensive Guide to Securing SSH on Ubuntu 22.04

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Verify if a media device or file is bootable

Published August 26, 2021

To verify if a removable media (e.g. USB, DVD, or ISO) is bootable, you could use file tool on Linux systems. The command file -s /path/to/media reads block special files, such as partitions, and outputs the information. To test this, I inserted RHEL 8.2 Installation ISO as a disk in a VM. The device path is /dev/sr0. Once I verified the disk is accessible, I ran file -s /dev/sr0. The output for RHEL Installation ISO shows the disk as a…

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Enabling Intel 10G SFP+ X520 Series module on Centos 7

Published September 7, 2019

By default, Centos 7 doesn’t support Intel’s 10G SFP+ X520 module. When you look at the dmesg you find the following error: “failed to load because an unsupported SFP+ or QSFP module type was detected.” The workaround is to allow unsupported SFP modules in the kernel by enabling ixgbe kernel module. Let’s start by editing /etc/default/grub file and change the line : to Now, we create the new grub configuration with the new option. Next, the configuration file for the…

(More…)Enabling Intel 10G SFP+ X520 Series module on Centos 7

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