Hello, and welcome to this presentation from Pluralsight.
My name is Andrew Mallett, and I'm going to be here as your instructor,
helping guiding you through the CompTIA Linux+: Troubleshooting course.
In this module, we not only introduce the course to you,
but we take a look at troubleshooting networks.
As we work our way through the complete course,
we're going to be looking at troubleshooting our Linux systems,
and this is going to include networks, memory and CPU,
our storage subsystems,
the problems that we might have with user access such as file permissions,
quotas,
and those sorts of things, as well as looking at systemd
and how we can diagnose systemd issues.
In this particular module, we're going to focus on troubleshooting our networks,
so we'll be looking at things such as name resolution,
interface information, and firewalling problems that we might come across.
So when you're sat comfortably, ready to begin, we shall start.
And we're going to look at the lab systems that we are using for this course.
As we go through and take a look, CompTIA recommend using a mix of
distributions, and we include AlmaLinux 8.5, so that then is a Red Hat
Enterprise Linux rebuild; Ubuntu 20.04; and OpenSUSE 15.2, so we have the big
three distributions well covered for you.
We're using Vagrant and VirtualBox for these machines as our
demonstrations. As such, we can build a virtual machine through a
Vagrantfile, and that is available from Git.
You are able to clone the Git repository, and you can see it on your screen
at the moment, and say that gives you access to the Vagrantfile, and the
Vagrantfile then will build the three virtual machines. And you know what, it
looks to me like it's time for a demonstration, and in this first
demonstration, we're going to start up our virtual machines and we're going
to be able to go through and take a look at the Vagrantfile that defines our
systems. And we can then verify connectivity, checking that we can
communicate from one virtual machine to the other, so just the very basics at
this stage.
So let's find that command line. Now when I go through and
take a look at my working directory,
we can see that I'm in Users, andrew, vagrant, and Linux+.
So I create a working directory for each of the projects that I need to
be working with. Here we're looking at CompTIA Linux+, so it kind of
makes sense, doesn't it, to have the Linux+ directory. If we go through
and cat out our Vagrantfile,
this then shows us the configuration. And we've got one main
configuration that starts the Vagrant.configure("2") and the
config block, but then within that main configuration block, we
have three virtual machines.
So we've got a virtual machine defining our almalinux/8 system, we've got a
definition that we call opensuse defining our opensuse 15.2 system, and of
course, we've got an ubuntu section, and in this section, of course, we're
setting up our ubuntu virtual machine.
If I want to bring all three of these machines up,
all I need to do is just run vagrant and up. If I don't specify a name,
it's bringing up the project rather than individual machines. So we can
see then that we're starting the alma, opensuse, and ubuntu machines.
The names are coming from the blocks that I've assigned to them. We can
allow this to start up,
it's only going to take a few minutes, but there's no real interest in
watching this. Now the reality is that probably took about 4 minutes, but
that's not bad to get three virtual machines created and started. I'm just
going to clear the screen, and I can then go through and just use an up
arrow key and we can go through and connect to one of those. So we can go
vagrant ssh, and then alma, hit Enter, and we're going to connect to our
AlmaLinux system. When I go through and run the command hostnamectl,
we can check the operating system that we're using and we can see that we're
using AlmaLinux 8.6 in this example. If we want to check that we've got
connectivity, then that's a really easy matter. We can go through then and ping
192.168.56.12, it should be the opensuse machine, so that's all up and running,
and then 13 should be our ubuntu machine.
And this system itself is 11, so you can see just at the bottom of
screen, but I can move that to the top. Hit the big Enter key, so we're
all up and running with our virtual machines.
Now there's not very much in this demonstration, but it's important
that you've got virtual machines that you can use to follow through in
the demonstrations, and I really do encourage that you set up your
virtual machines. Whether it's through Vagrant or whether you're
setting your virtual machines up in some other environment, it is
important for your learning that you're able to practice the commands that we demonstrate.