Hello and welcome to this. Cali fundamentals
lesson. I'm your host Robert Smith, and
I'm very excited to be here with you today. So you
may have already seen some networking commands. You
may be familiar with some networking commands, but maybe you're asking yourself.
You know, what are some of the differences between Linux
Cali and and windows with respect
to like, you know with Windows systems the
command to look at an interface may be different than
that of a Linux system or I tried a few
things on my Windows system that don't
seem to work on Linux. That's
what we're going to be looking at today. So when you walk away
from this lesson, you should have a high level again
a high level understanding of some key
networking commands and the high level understanding of
when these commands should be used based on our discussions and
points here today. So let's go ahead and Jump Right In
So I've just got a few commands here to get us started
and some screenshots that will go over here together. So
you've probably seen me using ping already and
you probably have run into ping and use
ping before in maybe school or maybe
you know, you're working on the support desk or something
like that or for an organization and you have to use ping essentially what
Ping does here is it's the same thing as it
is on a Windows system. It's just pinging an IP address or domain
name. Now the primary difference
to keep in mind between ping here is that if you get a
response and you don't do a control C when
you're using ping, it's just gonna continue to Ping until you
stop it. So you the difference here's with Windows when
you do a pain it'll ping a couple times and stop with a
linen space system. It's going to continue to
Ping until you stop it.
Now if config is going to be the way
that we look at interface information on Cali systems
Linux systems and general as you can see here. It gives
us a kind of layout on the interface IP
address the network address broadcast address Etc
gives us some packing information and additional stuff
like that. And then that's your loop back interface
there that's running on the system as
well. Now a command I wanted to add in here
because we're looking at you know, doing security testing and things
of that nature is if config promisc now,
there's a component in between the if
config and promiscuous that's not listed here because it varies
depending on what you want to make promiscuous now making an
interface promiscuous is essentially going
to mean that traffic it wouldn't otherwise pick up on or Listen
to It's going to pick up on everything and listen to everything and
this could be good for packet captures. You may notice when you
use tools like Wireshark or something like that that it
will
Promiscuous mode and collect all of the data coming across an
interface. So this is how you can manually turn
promiscuous mode on which you'll do is you'll notice that it
didn't have the interface information in between ifconfig
and promiscuous. And so it didn't find a device
when we add that ethernet 0 there like
we saw in the ifconfig information. We then
see after we do a quick check that it's running in
promiscuous mode, which is what we've got here. If you need to
turn that off you just add a minus sign in front of the premisk and
you'll notice here that it's no longer running in promiscuous mode
in that space like it was before now the other
command that I have here is trace route and what that
does is that's like a troubleshooting tool that can help
you kind of map out a path or or see the route
to a particular domain or
maybe a particular internal system.
Um, so in this case, I was just trying to get it to to look up
my Google DNS but it didn't reach it because it's got
a 30 hot Max. But in this case it would list out maybe
on the internal systems the pathway that a
route takes or that that it that the communications will
take to get to an end system. So with
those things in mind, let's do a quick check on
learning. So which command allows you
to set an interface to promiscuous mode?
All right, so you may be thinking. Well, I
know that if config is not the case because that shows
me interface information. I know what Ping does definitely
not ping ping doesn't do anything, but give us some feedback
from an inner from a system.
Promiscuous or promisc enabled is not
the case because we don't have any way that we're identifying, you
know, the interface that's going to run a
promiscuous mode and it's missing a component and we
didn't even use enabled when we were going through that together. So
the likely Choice here is going to be if config
you'll have an interface type with a number
and promisc and that will enable promisc and
remember if we want to disable promiscuous mode. We just put a
minus out in front of the promisc command. So
great job on that. Let's go ahead and jump into our next set
of commands.
Now these are a few additional commands that
will help you in things like troubleshooting looking
up domain information as well as looking up
your wireless interface information. Now, I don't have any wireless
cards or anything like that that are
running on my instant. So you'll notice when you look at
the IW config that it
doesn't have any Wireless extensions. And so that's okay because
I shouldn't I haven't said any of
that up, but if you did and you were troubleshooting that you would be
able to see here whether or not your instance was picking up your
wireless information.
Now as you get into security testing and
as you get into working with this distribution net stat is a
wonderful wonderful thing to know I actually
don't have a switch on the end of this which is like a dash in
a set of letters, but I love to use that's a
horrible a a ntp which gives me
several different outputs, but it's
primarily going to focus on the listening and connected systems
reports that
are open and listening and what they're connected to the netstat
in general is just going to give you a slew of
information about the different things that are listening and running on a system
but a great command to know when something you're gonna want to add to
your toolbox in this look up now, you'll
notice here that I used cybrary.it with this
does is it's going to point out some internal
systems that are handling DNS queries
and then it's going to give me the responses from
those systems like the Cyber systems.
Now, of course, this is for educational purposes.
Is this is you know the public DNS
information but you don't want to go any further
in doing any tool utilization or manipulation on these
systems without explicit permission. But if
you're doing some general troubleshooting internally, maybe you're trying
to figure out if your DNS server is busted or you're not getting responses
here or maybe you're not getting responses from here. That's a
good way to start troubleshooting and checking some information out.
An additional tool that you can use is called dig. It's a domain information
grouper and that's going to provide these feedbacks
over here and it's just a little bit more extensive. You'll see
we got the same answers with respect to the cybery
public DNS servers, you'll see
here that we also got feedback from our
internal DNS server. So this is just a
little bit more verbose than dig, but it
can definitely provide you some additional troubleshooting information as
you're trying to figure out or work your way through issues. So
with that in mind, let's do a check on learning which command
could assist in DNS troubleshooting issues.
Well, as we indicated earlier ping definitely,
you know could be used to maybe ping a server or
ping a DNS server and see if it responds that could be
used but that's not specifically going to give us
DNS information. If config, you know,
that is if there's an interface issue and you know,
that would not be directly related to DNS issues net stat
works with us on connections and what's actively
connected so dig again is
the domain information groper which we could use for
troubleshooting DNS issues. There are other tools that you could
use but in the context of this question, that is the correct
answer.
So that's it. We did a very brief lesson
today over some Network commands. We gave you a high
level introduction to things like Ping and ifconfig traceroute.
Netstat dig IW config.
All of those things are going to be foundational As
you move into troubleshooting your Linux
distributions as you work on, you know,
doing security testing and things of that nature and so with
all of that in mind. I want to thank you for your time again today, and
I look forward to seeing you soon.