How to define outgoing firewall rules on pFSense Rumi, February 24, 2020 LAN rules are defining rights to access internet services from your local network. So, if you block port 80 and 443 nobody from your LAN will be able to access internet. WAN rules are defining access to the resources in your LAN (or DMZ) from the internet. In this short… Continue Reading
Set DNS server address temporarily Rumi, February 24, 2020 Write it into /etc/resolv.conf: echo “nameserver 1.2.3.4″ | sudo tee /etc/resolv.conf Upon successful DHCP connection, it should be overwritten back to the “correct” DNS server. Continue Reading
Boot CentOS 8 / RHEL 8 Server in Single User Mode or root password reset Rumi, February 24, 2020February 24, 2020 Using “rd.break” keyword Reboot Your CentOS 8 or RHEL 8 Server and go to grub boot loader screen by interrupting auto boot and choose first line which includes the kernel (In case you have multiple kernel lines choose the appropriate one which suits to your environment). Below is the CentOS… Continue Reading
Clone KVM-based Virtual Machines on Redhat / CentOS Linux Rumi, February 24, 2020 Prerequisite: Operating System and Software Versions Operating System: – Redhat 7.3 Software: – libvirtd (libvirt) 2.0.0 Obtain Source Virtual Machine’s information Before we begin cloning any virtual machine we first need to obtain some basic information about it. The absolute minimum information required about the source virtual machine we are… Continue Reading
Ubuntu 18.04: Disable Netplan switch back to networking /etc/network/interfaces Rumi, February 24, 2020June 17, 2020 The following procedure works for Ubuntu 18.04 (Bionic Beaver) I. Reinstall the ifupdown package: # apt-get update # apt-get install ifupdown II. Configure your /etc/network/interfaces file with configuration stanzas such as: source /etc/network/interfaces.d/* # The loopback network interface auto lo iface lo inet loopback allow-hotplug enp0s3 auto enp0s3 iface enp0s3 inet static address 192.168.1.133 netmask 255.255.255.0 broadcast 192.168.1.255… Continue Reading
Disable swap in Linux Rumi, February 24, 2020 Identify configured swap devices and files with cat /proc/swaps. Turn off all swap devices and files with swapoff -a. Remove any matching reference found in /etc/fstab. Optional: Destroy any swap devices or files found in step 1 to prevent their reuse. Due to your concerns about leaking sensitive information, you… Continue Reading
Redhat / CentOS 8: text mode install guide Rumi, February 24, 2020 By default the RedHat 8 Linux installation will start in the graphical mode. In case you encounter some issues you have an option to force the text mode TTY installation. In this tutorial you will learn:How to modify GRUB boot entry to force text mode installation. Boot from the Redhat… Continue Reading
How to Enable /etc/rc.local with Systemd Rumi, February 24, 2020 If you are running a Linux distro that uses Systemd, then you may find that your command in /etc/rc.local file would not run on system boot. This guide explains how to enable /etc/rc.local script to run on system startup. Enable /etc/rc.local on Systemd If you type the following command in… Continue Reading
Join Several Partition Together To Form a Single Larger One On a Linux Using mhddfs Rumi, February 20, 2020 The easiest and fastest solution is to use mhddfs driver on Linux operating systems. It is a fuse-based file system for unifying several mount points into one. The mhddfs (fuse) file system allows to unite a several mount points (or directories) to the single one. So a one big filesystem… Continue Reading
Debian 7 wheezy – Certbot auto started failing with ’ No module named pip.__main__’ Rumi, February 9, 2020 If you’re using Debian 7 a.k.a wheezy which is end of life at this moment and you were using Let’s Encrypt was your SSL, then you might need some backward compatibility to continue. A possible work around for me as below: wget https://raw.githubusercontent.com/certbot/certbot/75499277be6699fd5a9b884837546391950a3ec9/certbot-auto chmod +x ./certbot-auto ./certbot-auto –no-self-upgrade For renewing… Continue Reading