Ubuntu 18.04 Lost Internet in Parallels

Ubuntu has changed how things have worked, and on the company network, you will need to set what DNS server is being used.

There is a settings place for this now, not tested yet:

Refer: https://vitux.com/how-to-change-dns-settings-in-ubuntu/

Refer: https://askubuntu.com/questions/1021884/no-internet-after-upgrade-from-16-04-to-18-04

Quick Test

If the /etc/resolv.conf is empty but you can ping 8.8.8.8, you can use the following as a quick test/patch, but you will need to use the following section for a complete fix.

$ echo "nameserver 8.8.8.8" | sudo tee /etc/resolv.conf > /dev/null

Permanent Fix

HALW DNS at time of writing was: 10.211.55.1

Use the following command to determine current IP address:
$ nmcli dev show | grep 'IP4.DNS'

Ubuntu might change completely how this works in the future, you can review this article here: https://www.techrepublic.com/article/how-to-set-dns-nameservers-in-ubuntu-server-18-04/

If the /etc/resolvconf/resolv.conf.d/head is empty then you have to repeat the command above after every restart except you do this:

$ sudo apt install resolvconf
$ echo "nameserver 8.8.8.8" | sudo tee -a /etc/resolvconf/resolv.conf.d/head > /dev/null
$ echo "nameserver 10.211.55.1" | sudo tee -a /etc/resolvconf/resolv.conf.d/head > /dev/null
$ echo "nameserver 8.8.4.4" | sudo tee -a /etc/resolvconf/resolv.conf.d/head > /dev/null

Then you have to restart the resolvconf and the networking

$ sudo systemctl enable resolvconf
$ sudo systemctl start resolvconf
$ sudo /etc/init.d/networking restart

 

Security Scan for Ubuntu

Refer: https://cisofy.com/lynis/

From John D'Costa- Run this to get full report of the system scan

$ sudo apt-get install lynis
$ lynis audit system -c

Looking for root kits:

https://www.theurbanpenguin.com/detecting-rootkits-with-rkhunter-in-ubuntu-18-04/

Install System Monitor Stacer

Install Stacer on Ubuntu 20.o4

Refer: https://linuxconfig.org/how-to-install-stacer-on-ubuntu-20-04-focal-fossa-linux-desktop

$ sudo apt install stacer
$ stacer

Install gdebi which is a lightweight *.deb Installer

We will be using the gdebi tool to install Stacer DEB file package. To install gdebi on your Ubuntu 18.04 system, open up terminal and enter:

You should be able to install this via the software store, and then you can just right-click and choose other applicatino to install a *.deb through the file manager.

Command Line Version
$ sudo apt install gdebi-core

Download Stacer

Navigate to Stacer download page and download the latest Stacer DEB package to your home directory. For example in this guide we will be installing Stacer 1.0.9. Let's start by downloading stacer via the wget command:

$ cd /tmp
$ wget https://jaist.dl.sourceforge.net/project/stacer/v1.0.9/stacer_1.0.9_amd64.deb

The above command downloaded Stacer Debian package into our user home directory.
Install Stacer

What remains is to use the gdebi command to install Stacer:

$ sudo gdebi ~/stacer.deb

Fix Terminal “Operation not permitted” Error in MacOS Mojave

Refer: http://osxdaily.com/2018/10/09/fix-operation-not-permitted-terminal-error-macos/

  • Pull down the  Apple menu and choose ‘System Preferences’
    Choose “Security & Privacy” control panel
  • Now select the “Privacy” tab, then from the left-side menu select “Full Disk Access”
  • Click the lock icon in the lower left corner of the preference panel and authenticate with an admin level login
  • Now click the [+] plus button to add an application with full disk access
  • Click the Plus button to add Terminal to Full Disk Access in macOS
  • Navigate to the /Applications/Utilities/ folder and choose “Terminal” to grant Terminal with Full Disk Access privileges
  • Select Terminal app to grant full disk access in MacOS
  • Relaunch Terminal, the “Operation not permitted” error messages will be gone

If you have not encountered the “Operation not permitted” error message in the Terminal of MacOS (Mojave 10.14 or later) yet, then it’s likely because you haven’t wandered into a directory or file path that has the additional access restrictions (or that you don’t use Terminal, in which case this entire article is not for you).

 

Scan for Wifi Connections using a Mac

Refer: https://www.howtogeek.com/197268/how-to-find-the-best-wi-fi-channel-for-your-router-on-any-operating-system/

  • On your Mac [Alt] + Wifi Icon
  • Open "Wireless Diagnostics"
  • Ignore Wizard and open Window, choose Scan
  • It will then rate your signals, and offer best 2.4 GHz and Best 5 Ghz channels