Hello and welcome to Command Line
Basics. In this video, we're going
to learn about Windows networking
commands, too.
I'm Christopher.
And let's begin.
So we're learning objectives for
this video. We're going to learn the
Pinkham and the traceroute
command and understand the
command and how we can use them at
the command line
assessment.
So you need to verify connectivity
to the domain controller.
When is the best command?
Is it A, get back.
B, IP config,
ci a.
lookup or D, ping?
The answer is D ping.
So where are you using Ping
to verify the connectivity?
And it's a very useful tool to
just reach out, ask
can you reach me?
And then it'll come straight back
and say, hey, I'm getting a
response.
So it's a very useful and easy
way to verify connectivity
between two IP addresses.
The get matched command is used to
display the Mac address for
a interface not to validate
connectivity similar
with the IP config command where we
see our Layer three address and that
information. But not to
validate that, hey, these two IP
addresses can actually talk to each
other and the NSA lookup command,
while it may go through your domain
controller for a DNS lookup,
if we're looking specifically for
the domain controller connectivity,
using ping is going to be our
best bet.
All right, so Ping, as we were
just learning, it is used to
validate the connectivity, it's
got a lot of very low overhead
and it is very easy to use.
So what we do is we just type in
ping and then the address and then
we'll say, hey, I can reach it
or no, I can't reach it.
I'm not getting a response.
So let's go ahead and do a quick
demonstration.
So let's say I want to thank Google.
I'm just going to type the Google
dot com.
And as you can see, we are getting
replies from Google.
So it has about twenty
five milliseconds, twenty to twenty,
twenty three.
So really good response
time and it's very useful.
We got a zero percent loss as
we see. So we know that we're
connected to the Internet and it's
working very properly.
Now, the traceroute command is
very similar to Ping, but it adds
more functionality on top of that as
well. So what it does is it
will go through every single hop
in between the
I.P. address, the event
and the destination, and it will
say, hey, I took these
many hops and at these specific
addresses in order to get to
your destination.
So this is very useful to help
troubleshoot on a network and
help troubleshoot latency as well.
So this is a useful command.
It is very similar to Ping.
So let's go ahead and take a look at
this.
It's going to do Traceroute
Google dot com,
and it does take a little bit of
time because it's constantly
reaching back and forth between
the different systems
in order to validate the
connectivity.
So as you can see, I'm already on a
third hop
this first hop here.
It is leaving my local network
because it is connecting to my
default gateway here.
And as you can see, it's hopping
between a few different IP
addresses.
And it does take a little bit of
time, so don't be too worried about
it.
This is also a useful way to help
determine if something
is routing somewhere.
It shouldn't be because you'll be
able to see everywhere that it's
going.
It looks like is almost
there.
And if you're not familiar with the
term of hop and networking, it is
if we change between a writer going
between multiple
different networks.
All right. So it looks like we've
completed we took 11 hops
to get there, but we were able
to get to the Google dotcom
and get a response.
And we have the AAFP command, this
is the address, resolution,
protocol, command.
And what this does is it helps
store information about
IP addresses and MAC addresses
for layer two.
And if you're not familiar with our
its whole purpose is to
request the Mac address on a local
network for a known IP address.
So when the computer connects to
a network and gets a
address, that's a dynamic
host configuration protocol address
by automatically
it will know, hey, this is
my default gateway is one
nine two one six eight one down one.
But with the system does not
know is not know the Mac
address that layer to address on
the local network for that IP.
So when you do reach out and say,
hey, I know I need
to reach this IP, but I
don't know what the layer to address
is and it sends out a broadcast
to the entire local network.
And any machine that does not
have that one nine two one six eight
one don't want to address just
drops. It says, hey, this is not
for me, I'm going to ignore it.
But the machine that does have
that IP address configured, it's
going to say, hey, that's me.
Here's all my information.
This is my Mac address, this is how
you can reach me.
So for our local machine, when
it sends it out, it'll get that
response back and they'll say, hey,
all right. So for any packet, that's
my default gateway.
I'm going to send it out to this Mac
address and we'll call the day
so we can also use the dash
a switch.
And this will show us our our cash
because it is cached for a certain
amount of time.
That way, the computer does not have
to keep constantly asking for
what a specific Mac addresses
on the network.
So let's take a look.
Do AAFP dash
and it has all these different
stored Mac addresses for
each interface.
So as we can see, I have a whole
bunch of different ones
that are very useful.
All right, so why is
our cash important?
Is it a it can be poison
be it can be used to determine
a host IP address.
See, it is using layer
seven protocols or deals.
It can corrupt the file system.
The answer is A, it can be poisoned.
The Aakash is a very useful
protocol.
But let's say in our example,
an attacker responded that
quicker than the system
that actually owned that IP address.
What this does is it effectively
poisons the cash
for the local machine that was
reaching out, asking for it,
and that machine will submit all
the request to the attacker.
And then on that end, the attacker
can submit it to the correct actual
address, but it can listen
or change information
for those packets while they're on
the way.
So this is a AAFP cash
poisoning attack.
And it's important to keep in mind
and we can validate if the
computer has the correct
information using the
dash a command to look at that
cache.
It is not used to determine the host
IP address.
That's a completely different
configuration in IP config
does not use layer seven protocols.
There's a layer to protocol.
Only an hour cannot
corrupt the file system
that is completely separate
in the networking stack and the file
system.
So in this video we learned the
Pinkham in the Tracer Command
understood the argument how we can
use these for networking at
the Windows command line.
And I hope to see you in the next
video.